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Merge remote-tracking branch 'LCTT/master'
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Xingyu.Wang
commit
07019d648e
@ -11,9 +11,9 @@
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||||
|
||||
这可以通过 6 种方法来实现，下面我来演示一下怎么做。
|
||||
|
||||
### 方法一：使用 `Dmidecode` 命令
|
||||
### 方法一：使用 dmidecode 命令
|
||||
|
||||
`Dmidecode` 是一个读取电脑 DMI（<ruby>桌面管理接口<rt>Desktop Management Interface</rt></ruby>）表内容并且以人类可读的格式显示系统硬件信息的工具。（也有人说是读取 SMBIOS —— <ruby>系统管理 BIOS<rt>System Management BIOS</rt></ruby>）
|
||||
`dmidecode` 是一个读取电脑 DMI（<ruby>桌面管理接口<rt>Desktop Management Interface</rt></ruby>）表内容并且以人类可读的格式显示系统硬件信息的工具。（也有人说是读取 SMBIOS —— <ruby>系统管理 BIOS<rt>System Management BIOS</rt></ruby>）
|
||||
|
||||
这个表包含系统硬件组件的说明，也包含如序列号、制造商、发布日期以及 BIOS 修订版本号等其它有用的信息。
|
||||
|
||||
@ -50,7 +50,7 @@ System Boot Information
|
||||
|
||||
**推荐阅读：** [Dmidecode –– 获取 Linux 系统硬件信息的简单方式][1]
|
||||
|
||||
### 方法二：使用 `inxi` 命令
|
||||
### 方法二：使用 inxi 命令
|
||||
|
||||
`inxi` 是 Linux 上查看硬件信息的一个灵巧的小工具，它提供了大量的选项来获取所有硬件信息，这是我在现有的其它 Linux 工具集里所没见到过的。它是从 locsmif 编写的古老的但至今看来都异常灵活的 `infobash` fork 出来的。
|
||||
|
||||
@ -64,7 +64,7 @@ Machine: Device: server System: IBM product: N/A v: 0B serial: MK2RL11
|
||||
|
||||
**推荐阅读：** [inxi —— 一个很棒的查看 Linux 硬件信息的工具][2]
|
||||
|
||||
### 方法三：使用 `lshw` 命令
|
||||
### 方法三：使用 lshw 命令
|
||||
|
||||
`lshw`（指<ruby>硬件监听器<rt>Hardware Lister</rt></ruby>）是一个小巧灵活的工具，可以生成如内存配置、固件版本、主板配置、CPU 版本和速度、缓存配置、USB、网卡、显卡、多媒体、打印机以及总线速度等机器中各种硬件组件的详细报告。
|
||||
|
||||
@ -87,7 +87,7 @@ enal-dbo01t
|
||||
|
||||
**推荐阅读：** [LSHW (Hardware Lister) –– 获取 Linux 硬件信息的灵巧的小工具][3]
|
||||
|
||||
### 方法四：使用 `/sys` 文件系统
|
||||
### 方法四：使用 /sys 文件系统
|
||||
|
||||
内核在 `/sys` 目录下的文件中公开了一些 DMI 信息。因此，我们可以通过如下方式运行 `grep` 命令来轻易地获取机器类型。
|
||||
|
||||
@ -111,7 +111,7 @@ MK2RL11
|
||||
-[VVE134MUS-1.50]-
|
||||
```
|
||||
|
||||
### 方法五：使用 `dmesg` 命令
|
||||
### 方法五：使用 dmesg 命令
|
||||
|
||||
`dmesg` 命令是在 Linux 上 `syslogd` 或 `klogd` 启动前用来记录内核消息（启动阶段的消息）的。它通过读取内核的环形缓冲区来获取数据。在排查问题或只是尝试获取系统硬件信息时，`dmesg` 非常有用。
|
||||
|
||||
@ -120,7 +120,7 @@ MK2RL11
|
||||
DMI: System x2530 M4: -[1214AC1]-/00Y8494, BIOS -[VVE134MUS-1.50]- 08/30/2013
|
||||
```
|
||||
|
||||
### 方法六：使用 `hwinfo` 命令
|
||||
### 方法六：使用 hwinfo 命令
|
||||
|
||||
`hwinfo`（<ruby>硬件信息<rt>hardware information</rt></ruby>）是另一个很棒的工具，用于检测当前系统存的硬件，并以人类可读的方式显示各种硬件模块的详细信息。
|
||||
|
||||
630
published/20180726 The evolution of package managers.md
Normal file
630
published/20180726 The evolution of package managers.md
Normal file
@ -0,0 +1,630 @@
|
||||
包管理器的进化
|
||||
======
|
||||
|
||||
> 包管理器在 Linux 软件管理中扮演了重要角色。这里对一些主要的包管理器进行了对比。
|
||||
|
||||
|
||||
|
||||
今天，每个可计算设备都会使用某种软件来完成预定的任务。在软件开发的上古时期，为了找出软件中的“虫”和其它缺陷，软件会被严格的测试。在近十年间，软件被通过互联网来频繁分发，以试图通过持续不断的安装新版本的软件来解决软件的缺陷问题。在很多情况下，每个独立的应用软件都有其自带的更新器。而其它一些软件则让用户自己去搞明白如何获取和升级软件。
|
||||
|
||||
Linux 较早采用了维护一个中心化的软件仓库来发布软件更新这种做法，用户可以在这个软件仓库里查找并安装软件。在这篇文章里， 笔者将回顾在 Linux 上的如何进行软件安装的历史，以及现代操作系统如何保持更新以应对[软件安全漏洞（CVE）][1]不断的曝光。
|
||||
|
||||
### 那么在包管理器出现之前在 Linux 上是如何安装软件的呢？
|
||||
|
||||
曾几何时，软件都是通过 FTP 或邮件列表（LCTT 译注：即通过邮件列表发布源代码的补丁包）来分发的（最终这些发布方式在互联网的迅猛发展下都演化成为一个个现今常见的软件发布网站）。（一般在一个 tar 文件中）只有一个非常小的文件包含了创建二进制的说明。你需要做的是先解压这个包，然后仔细阅读当中的 `README` 文件， 如果你的系统上恰好有 GCC（LCTT 译注：GNU C Compiler）或者其它厂商的 C 编译器的话，你得首先运行 `./configure` 脚本，并在脚本后添加相应的参数，如库函数的路径、创建可执行文件的路径等等。除此之外，这个配置过程也会检查你操作系统上的软件依赖是否满足安装要求。如果缺失了任何主要的依赖，该配置脚本会退出不再继续安装，直到你满足了该依赖。如果该配置脚本正常执行完毕，将会创建一个 `Makefile` 文件。
|
||||
|
||||
当有了一个 `Makefile` 文件时， 你就可以接下去执行 `make` 命令（该命令由你所使用的编译器提供）。`make` 命令也有很多参数，被称为 `make` <ruby>标识<rt>flag</rt></ruby>，这些标识能为你的系统优化最终生成出来的二进制可执行文件。在计算机世界的早期，这些优化是非常重要的，因为彼时的计算机硬件正在为了跟上软件迅速的发展而疲于奔命。今日今时，编译标识变得更加通用而不是为了优化哪些具体的硬件型号，这得益于现代硬件和现代软件相比已经变得成本低廉，唾手可得。
|
||||
|
||||
最后，在 `make` 完成之后， 你需要运行 `make install` （或 `sudo make install`）（LCTT 译注：依赖于你的用户权限） 来“真正”将这个软件安装到你的系统上。可以想象，为你系统上的每一个软件都执行上述的流程将是多么无聊费时，更不用说如果更新一个已经安装的软件将会多复杂，多么需要精力投入。（LCTT 译注：上述流程也称 CMMI 安装， 即Configure、Make、Make Install）
|
||||
|
||||
### 那么软件包是什么？
|
||||
|
||||
<ruby>软件包<rt>package</rt></ruby>（LCTT 译注：下文简称“包”）这个概念是用来解决在软件安装、升级过程中的复杂性的。包将软件安装升级中需要的多个数据文件合并成一个单独的文件，这将便于传输和（通过压缩文件来）减小存储空间（LCTT 译注：减少存储空间这一点在现在已经不再重要），包中的二进制可执行文件已根据开发者所选择的编译标识预编译。包本身包括了所有需要的元数据，如软件的名字、软件的说明、版本号，以及要运行这个软件所需要的依赖包等等。
|
||||
|
||||
不同流派的 Linux 发行版都创造了它们自己的包格式，其中最常用的包格式有：
|
||||
|
||||
* .deb：这种包格式由 Debian、Ubuntu、Linux Mint 以及其它的变种使用。这是最早被发明的包类型。
|
||||
* .rpm：这种包格式最初被称作<ruby>红帽包管理器<rt>Red Hat Package Manager</rt></ruby>（LCTT 译注： 取自英文的首字母）。使用这种包的 Linux 发行版有 Red Hat、Fedora、SUSE 以及其它一些较小的发行版。
|
||||
* .tar.xz：这种包格式只是一个软件压缩包而已，这是 Arch Linux 所使用的格式。（LCTT 译注：这种格式无需特别的包管理器，解压即可）
|
||||
|
||||
尽管上述的包格式自身并不能直接管理软件的依赖问题，但是它们的出现将 Linux 软件包管理向前推进了一大步。
|
||||
|
||||
### 软件仓库到底是什么？
|
||||
|
||||
多年以前（当智能电话还没有像现在这样流行时），非 Linux 世界的用户是很难理解软件仓库的概念的。甚至今时今日，大多数完全工作在 Windows 下的用户还是习惯于打开浏览器，搜索要安装的软件（或升级包），下载然后安装。但是，智能电话传播了软件“商店”（LCTT 译注： 对应 Linux 里的软件仓库）这样一个概念。智能电话用户获取软件的方式和包管理器的工作方式已经非常相近了。些许不同的是，尽管大多数软件商店还在费力美化它的图形界面来吸引用户，大多数 Linux 用户还是愿意使用命令行来安装软件。总而言之，软件仓库是一个中心化的可安装软件列表，上面列举了在当前系统中预先配置好的软件仓库里所有可以安装的软件。下面我们举一些例子来说在各个不同的 Linux 发行版下如何在对应的软件仓库里搜寻某个特定的软件（输出有截断）。
|
||||
|
||||
在 Arch Linux 下使用 `aurman`：
|
||||
|
||||
```
|
||||
user@arch ~ $ aurman -Ss kate
|
||||
|
||||
extra/kate 18.04.2-2 (kde-applications kdebase)
|
||||
Advanced Text Editor
|
||||
aur/kate-root 18.04.0-1 (11, 1.139399)
|
||||
Advanced Text Editor, patched to be able to run as root
|
||||
aur/kate-git r15288.15d26a7-1 (1, 1e-06)
|
||||
An advanced editor component which is used in numerous KDE applications requiring a text editing component
|
||||
```
|
||||
|
||||
在 CentOS 7 下使用 `yum`：
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum search kate
|
||||
|
||||
kate-devel.x86_64 : Development files for kate
|
||||
kate-libs.x86_64 : Runtime files for kate
|
||||
kate-part.x86_64 : Kate kpart plugin
|
||||
```
|
||||
|
||||
|
||||
在 Ubuntu 下使用 `apt`：
|
||||
|
||||
```
|
||||
user@ubuntu ~ $ apt search kate
|
||||
Sorting... Done
|
||||
Full Text Search... Done
|
||||
|
||||
kate/xenial 4:15.12.3-0ubuntu2 amd64
|
||||
powerful text editor
|
||||
|
||||
kate-data/xenial,xenial 4:4.14.3-0ubuntu4 all
|
||||
shared data files for Kate text editor
|
||||
|
||||
kate-dbg/xenial 4:15.12.3-0ubuntu2 amd64
|
||||
debugging symbols for Kate
|
||||
|
||||
kate5-data/xenial,xenial 4:15.12.3-0ubuntu2 all
|
||||
shared data files for Kate text editor
|
||||
```
|
||||
|
||||
### 最好用的包管理器有哪些？
|
||||
|
||||
如上示例的输出，包管理器用来和相应的软件仓库交互，获取软件的相应信息。下面对它们做一个简短介绍。
|
||||
|
||||
#### 基于 PRM 包格式的包管理器
|
||||
|
||||
更新基于 RPM 的系统，特别是那些基于 Red Hat 技术的系统，有着非常有趣而又详实的历史。实际上，现在的 [YUM][2] 版本（用于 企业级发行版）和 [DNF][3]（用于社区版）就融合了好几个开源项目来提供它们现在的功能。
|
||||
|
||||
Red Hat 最初使用的包管理器，被称为 [RPM][4]（<ruby>红帽包管理器<rt>Red Hat Package Manager</rt></ruby>），时至今日还在使用着。不过，它的主要作用是安装本地的 RPM 包，而不是去在软件仓库搜索软件。后来开发了一个叫 `up2date` 的包管理器，它被用来通知用户包的最新更新，还能让用户在远程仓库里搜索软件并便捷的安装软件的依赖。尽管这个包管理器尽职尽责，但一些社区成员还是感觉 `up2date` 有着明显的不足。
|
||||
|
||||
现在的 YUM 来自于好几个不同社区的努力。1999-2001 年一群在 Terra Soft Solution 的伙计们开发了<ruby>黄狗更新器<rt>Yellowdog Updater</rt></ruby>（YUP），将其作为 [Yellow Dog Linux][5] 图形安装器的后端。<ruby>杜克大学<rt>Duke University</rt></ruby>喜欢这个主意就决定去增强它的功能，它们开发了<ruby>[黄狗更新器--修改版][16]<rt>Yellowdog Updater, Modified</rt></ruby>（YUM），这最终被用来帮助管理杜克大学的 Red Hat 系统。Yum 壮大的很快，到 2005 年，它已经被超过一半的 Linux 市场所采用。今日，几乎所有的使用 RPM 的的 Linux 都会使用 YUM 来进行包管理（当然也有一些例外）。
|
||||
|
||||
##### 使用 YUM
|
||||
|
||||
为了能让 YUM 正常工作，比如从一个软件仓库里下载和安装包，仓库说明文件必须放在 `/etc/yum.repos.d/` 目录下且必须以 `.repo` 作为扩展名。如下是一个示例文件的内容：
|
||||
|
||||
```
|
||||
[local_base]
|
||||
name=Base CentOS (local)
|
||||
baseurl=http://7-repo.apps.home.local/yum-repo/7/
|
||||
enabled=1
|
||||
gpgcheck=0
|
||||
```
|
||||
|
||||
这是笔者本地仓库之一，这也是为什么 gpgcheck 值为 0 的原因。如果这个值为 1 的话，每个包都需要被密钥签名，相应的密钥（的公钥）也要导入到安装软件的系统上。因为这个软件仓库是笔者本人维护的且笔者信任这个仓库里的包，所以就不去对它们一一签名了。
|
||||
|
||||
当一个仓库文件准备好时，你就能开始从远程软件仓库开始安装文件了。最基本的命令是 `yum update`，这将会更新所有已安装的包。你也不需要用特殊的命令来更新仓库本身，所有这一切都已自动完成了。运行命令示例如下：
|
||||
|
||||
```
|
||||
[user@centos ~]$ sudo yum update
|
||||
Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager
|
||||
local_base | 3.6 kB 00:00:00
|
||||
local_epel | 2.9 kB 00:00:00
|
||||
local_rpm_forge | 1.9 kB 00:00:00
|
||||
local_updates | 3.4 kB 00:00:00
|
||||
spideroak-one-stable | 2.9 kB 00:00:00
|
||||
zfs | 2.9 kB 00:00:00
|
||||
(1/6): local_base/group_gz | 166 kB 00:00:00
|
||||
(2/6): local_updates/primary_db | 2.7 MB 00:00:00
|
||||
(3/6): local_base/primary_db | 5.9 MB 00:00:00
|
||||
(4/6): spideroak-one-stable/primary_db | 12 kB 00:00:00
|
||||
(5/6): local_epel/primary_db | 6.3 MB 00:00:00
|
||||
(6/6): zfs/x86_64/primary_db | 78 kB 00:00:00
|
||||
local_rpm_forge/primary_db | 125 kB 00:00:00
|
||||
Determining fastest mirrors
|
||||
Resolving Dependencies
|
||||
--> Running transaction check
|
||||
```
|
||||
|
||||
如果你确定想让 YUM 在执行任何命令时不要停下来等待用户输入，你可以命令里放 `-y` 标志，如 `yum update -y`。
|
||||
|
||||
安装一个新包很简单。首先，用 `yum search` 搜索包的名字。
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum search kate
|
||||
|
||||
artwiz-aleczapka-kates-fonts.noarch : Kates font in Artwiz family
|
||||
ghc-highlighting-kate-devel.x86_64 : Haskell highlighting-kate library development files
|
||||
kate-devel.i686 : Development files for kate
|
||||
kate-devel.x86_64 : Development files for kate
|
||||
kate-libs.i686 : Runtime files for kate
|
||||
kate-libs.x86_64 : Runtime files for kate
|
||||
kate-part.i686 : Kate kpart plugin
|
||||
```
|
||||
|
||||
当你找到你要安装的包后，你可以用 `sudo yum install kate-devel -y` 来安装。如果你安装了你不需要的软件，可以用 `sudo yum remove kdate-devel -y` 来从系统上删除它，默认情况下，YUM 会删除软件包以及它的依赖。
|
||||
|
||||
有些时候你甚至都不清楚要安装的包的名称，你只知道某个实用程序的名字。（LCTT 译注：可以理解实用程序是安装包的子集）。例如，你想找实用程序 `updatedb`（它是用来创建/更新由 `locate` 命令所使用的数据库的），直接试图安装 `updatedb` 会返回下面的结果：
|
||||
|
||||
```
|
||||
[user@centos ~]$ sudo yum install updatedb
|
||||
Loaded plugins: fastestmirror, langpacks
|
||||
Loading mirror speeds from cached hostfile
|
||||
No package updatedb available.
|
||||
Error: Nothing to do
|
||||
```
|
||||
|
||||
你可以搜索实用程序来自哪个包：
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum whatprovides *updatedb
|
||||
Loaded plugins: fastestmirror, langpacks
|
||||
Loading mirror speeds from cached hostfile
|
||||
|
||||
bacula-director-5.2.13-23.1.el7.x86_64 : Bacula Director files
|
||||
Repo : local_base
|
||||
Matched from:
|
||||
Filename : /usr/share/doc/bacula-director-5.2.13/updatedb
|
||||
|
||||
mlocate-0.26-8.el7.x86_64 : An utility for finding files by name
|
||||
Repo : local_base
|
||||
Matched from:
|
||||
Filename : /usr/bin/updatedb
|
||||
```
|
||||
|
||||
笔者在前面使用星号的原因是 `yum whatprovides` 使用路径去匹配文件。笔者不确定文件在哪里，所以使用星号去指代任意路径。
|
||||
|
||||
当然 YUM 还有很多其它的可选项。这里笔者希望你能够自己查看 YUM 的手册来找到其它额外的可选项。
|
||||
|
||||
<ruby>[时髦的 Yum][7]<rt>Dandified Yum</rt></ruby>（DNF）是 YUM 的下一代接班人。从 Fedora 18 开始被作为包管理器引入系统，不过它并没有被企业版所采用，所以它只在 Fedora（以及变种）上占据了主导地位。DNF 的用法和 YUM 几乎一模一样，它主要是用来解决性能问题、晦涩无说明的API、缓慢/不可靠的依赖解析，以及偶尔的高内存占用。DNF 是作为 YUM 的直接替代品来开发的，因此这里笔者就不重复它的用法了，你只用简单的将 `yum` 替换为 `dnf` 就行了。
|
||||
|
||||
##### 使用 Zypper
|
||||
|
||||
[Zypper][8] 是用来管理 RPM 包的另外一个包管理器。这个包管理器主要用于 [SUSE][9]（和 [openSUSE][10]），在[MeeGo][11]、[Sailfish OS][12]、[Tizen][13] 上也有使用。它最初开发于 2006 年，已经经过了多次迭代。除了作为系统管理工具 [YaST][14] 的后端和有些用户认为它比 YUM 要快之外也没有什么好多说的。
|
||||
|
||||
Zypper 使用与 YUM 非常相像。它被用来搜索、更新、安装和删除包，简单的使用命令如下：
|
||||
|
||||
```
|
||||
zypper search kate
|
||||
zypper update
|
||||
zypper install kate
|
||||
zypper remove kate
|
||||
```
|
||||
|
||||
主要的不同来自于使用 Zypper 的系统在添加软件仓库的做法上，Zypper 使用包管理器本身来添加软件仓库。最通用的方法是通过一个 URL，但是 Zypper 也支持从仓库文件里导入。
|
||||
|
||||
```
|
||||
suse:~ # zypper addrepo http://download.videolan.org/pub/vlc/SuSE/15.0 vlc
|
||||
Adding repository 'vlc' [done]
|
||||
Repository 'vlc' successfully added
|
||||
|
||||
Enabled : Yes
|
||||
Autorefresh : No
|
||||
GPG Check : Yes
|
||||
URI : http://download.videolan.org/pub/vlc/SuSE/15.0
|
||||
Priority : 99
|
||||
```
|
||||
|
||||
你也能用相似的手段来删除软件仓库：
|
||||
|
||||
```
|
||||
suse:~ # zypper removerepo vlc
|
||||
Removing repository 'vlc' ...................................[done]
|
||||
Repository 'vlc' has been removed.
|
||||
```
|
||||
|
||||
使用 `zypper repos` 命令来查看当前系统上的软件仓库的状态：
|
||||
|
||||
```
|
||||
suse:~ # zypper repos
|
||||
Repository priorities are without effect. All enabled repositories share the same priority.
|
||||
|
||||
# | Alias | Name | Enabled | GPG Check | Refresh
|
||||
---|---------------------------|-----------------------------------------|---------|-----------|--------
|
||||
1 | repo-debug | openSUSE-Leap-15.0-Debug | No | ---- | ----
|
||||
2 | repo-debug-non-oss | openSUSE-Leap-15.0-Debug-Non-Oss | No | ---- | ----
|
||||
3 | repo-debug-update | openSUSE-Leap-15.0-Update-Debug | No | ---- | ----
|
||||
4 | repo-debug-update-non-oss | openSUSE-Leap-15.0-Update-Debug-Non-Oss | No | ---- | ----
|
||||
5 | repo-non-oss | openSUSE-Leap-15.0-Non-Oss | Yes | ( p) Yes | Yes
|
||||
6 | repo-oss | openSUSE-Leap-15.0-Oss | Yes | ( p) Yes | Yes
|
||||
```
|
||||
|
||||
`zypper` 甚至还有和 YUM 相同的功能：搜索包含文件或二进制的包。和 YUM 有所不同的是，它在命令行里使用破折号（但是这个搜索方法现在被废除了……）
|
||||
|
||||
```
|
||||
localhost:~ # zypper what-provides kate
|
||||
Command 'what-provides' is replaced by 'search --provides --match-exact'.
|
||||
See 'help search' for all available options.
|
||||
Loading repository data...
|
||||
Reading installed packages...
|
||||
|
||||
S | Name | Summary | Type
|
||||
---|------|----------------------|------------
|
||||
i+ | Kate | Advanced Text Editor | application
|
||||
i | kate | Advanced Text Editor | package
|
||||
```
|
||||
|
||||
YUM、DNF 和 Zypper 三剑客拥有的功能比在这篇小文里讨论的要多得多，请查看官方文档来得到更深入的信息。
|
||||
|
||||
#### 基于 Debian 的包管理器
|
||||
|
||||
作为一个现今仍在被积极维护的最古老的 Linux 发行版之一，Debian 的包管理系统和基于 RPM 的系统的包管理系统非常类似。它使用扩展名为 “.deb” 的包，这种文件能被一个叫做 `dpkg` 的工具所管理。`dpgk` 同 `rpm` 非常相似，它被设计成用来管理在存在于本地（硬盘）的包。它不会去做包依赖关系解析（它会做依赖关系检查，不过仅此而已），而且在同远程软件仓库交互上也并无可靠的途径。为了提高用户体验并便于使用，Debian 项目开始了一个软件项目：Deity，最终这个代号被丢弃并改成了现在的 <ruby>[高级打包工具][15]<rt>Advanced Package Tool</rt></ruby>（APT）。
|
||||
|
||||
在 1998 年，APT 测试版本发布（甚至早于 1999 年的 Debian 2.1 发布），许多用户认为 APT 是基于 Debian 系统标配功能之一。APT 使用了和 RPM 一样的风格来管理仓库，不过和 YUM 使用单独的 .repo 文件不同，APT 曾经使用 `/etc/apt/sources.list` 文件来管理软件仓库，后来的变成也可以使用 `/etc/apt/sources.d` 目录来管理。如同基于 RPM 的系统一样，你也有很多很多选项配置来完成同样的事情。你可以编辑和创建前述的文件，或者使用图形界面来完成上述工作（如 Ubuntu 的“Software & Updates”），为了给所有的 Linux 发行版统一的待遇，笔者将会只介绍命令行的选项。
|
||||
要想不直接编辑文件内容而直接增加软件仓库的话，可以用如下命令：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-add-repository "deb http://APT.spideroak.com/ubuntu-spideroak-hardy/ release restricted"
|
||||
```
|
||||
|
||||
这个命令将会在 `/etc/apt/sources.list.d` 目录里创建一个 `spideroakone.list` 文件。显而易见，文件里的内容依赖于所添加的软件仓库，如果你想加一个<ruby>个人软件包存档<rt>Personal Package Archive</rt></ruby>（PPA）的话，你可以用如下的办法：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-add-repository ppa:gnome-desktop
|
||||
```
|
||||
|
||||
注意： Debian 原生并不支持本地 PPA 。
|
||||
|
||||
在添加了一个软件仓库后，需要通知基于 Debian 的系统有一个新的仓库可以用来搜索包，可以运行 `apt-get update` 来完成：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get update
|
||||
Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]
|
||||
Hit:2 http://APT.spideroak.com/ubuntu-spideroak-hardy release InRelease
|
||||
Hit:3 http://ca.archive.ubuntu.com/ubuntu xenial InRelease
|
||||
Get:4 http://ca.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
|
||||
Get:5 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages [517 kB]
|
||||
Get:6 http://security.ubuntu.com/ubuntu xenial-security/main i386 Packages [455 kB]
|
||||
Get:7 http://security.ubuntu.com/ubuntu xenial-security/main Translation-en [221 kB]
|
||||
...
|
||||
|
||||
Fetched 6,399 kB in 3s (2,017 kB/s)
|
||||
Reading package lists... Done
|
||||
```
|
||||
|
||||
现在新的软件仓库已经在你的系统里安装并更新好了，你可以用 `apt-cache` 来搜索你想要的包了。
|
||||
|
||||
```
|
||||
user@ubuntu:~$ apt-cache search kate
|
||||
aterm-ml - Afterstep XVT - a VT102 emulator for the X window system
|
||||
frescobaldi - Qt4 LilyPond sheet music editor
|
||||
gitit - Wiki engine backed by a git or darcs filestore
|
||||
jedit - Plugin-based editor for programmers
|
||||
kate - powerful text editor
|
||||
kate-data - shared data files for Kate text editor
|
||||
kate-dbg - debugging symbols for Kate
|
||||
katepart - embeddable text editor component
|
||||
```
|
||||
|
||||
要安装 kate，简单的运行下面的命令：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get install kate
|
||||
```
|
||||
|
||||
要是删除一个包，使用 `apt-get remove`：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get remove kate
|
||||
```
|
||||
|
||||
要探索一个包的话，APT 并没有提供一个类似于 `yum whatprovides` 的功能，如果你想深入包内部去确定一个特定的文件的话，也有一些别的方法能帮你完成这个目标，
|
||||
|
||||
如： 用 `dpkg`
|
||||
|
||||
```
|
||||
user@ubuntu:~$ dpkg -S /bin/ls
|
||||
coreutils: /bin/ls
|
||||
```
|
||||
|
||||
或者： `apt-file`
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get install apt-file -y
|
||||
user@ubuntu:~$ sudo apt-file update
|
||||
user@ubuntu:~$ apt-file search kate
|
||||
```
|
||||
|
||||
与 `yum whatprovides` 不同的是，`apt-file search` 的问题是因为自动添加了通配符搜索而输出过于详细（除非你知道确切的路径），最终在结果里包括了所有包含有 “kate” 的结果。
|
||||
|
||||
```
|
||||
kate: /usr/bin/kate
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katebacktracebrowserplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katebuildplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katecloseexceptplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katectagsplugin.so
|
||||
```
|
||||
|
||||
上面这些例子大部分都使用了 `apt-get`。请注意现今大多数的 Ubuntu 教程里都径直使用了 `apt`。 单独一个 `apt` 设计用来实现那些最常用的 APT 命令的。`apt` 命令看上去是用来整合那些被分散在 `apt-get`、`apt-cache` 以及其它一些命令的的功能的。它还加上了一些额外的改进，如色彩、进度条以及其它一些小功能。上述的常用命令都能被 `apt` 替代，但是并不是所有的基于 Debian 的系统都能使用 `apt` 接受安全包补丁的，你有可能要安装额外的包的实现上述功能。
|
||||
|
||||
#### 基于 Arch 的包管理器
|
||||
|
||||
[Arch Linux][16] 使用称为 [packman][17] 的包管理器。和 .deb 以及 .rpm 不同，它使用更为传统的 LZMA2 压缩包形式 .tar.xz 。这可以使 Arch Linux 包能够比其它形式的压缩包（如 gzip）有更小的尺寸。自从 2002 年首次发布以来， `pacman` 一直在稳定发布和改善。使用它最大的好处之一是它支持 [Arch Build System][18]，这是一个从源代码级别构建包的构建系统。该构建系统借助一个叫 `PKGBUILD` 的文件，这个文件包含了如版本号、发布号、依赖等等的元数据，以及一个为编译遵守 Arch Linux 需求的包所需要的带有必要的编译选项的脚本。而编译的结果就是前文所提的被 `pacman` 所使用的 .tar.xz 的文件。
|
||||
|
||||
上述的这套系统技术上导致了 <ruby>[Arch 用户仓库][19]<rt>Arch User Respository</rt></ruby>（AUR）的产生，这是一个社区驱动的软件仓库，仓库里包括有 `PKGBUILD` 文件以及支持补丁或脚本。这给 Arch Linux 带了无穷无尽的软件资源。最为明显的好处是如果一个用户（或开发者）希望他开发的软件能被广大公众所使用，他不必通过官方途径去在主流软件仓库获得许可。而不利之处则是它必须将依赖社区的流程，类似于 [Docker Hub][20]、
|
||||
Canonical 的 Snap Packages（LCTT 译注： Canonical 是 Ubuntu 的发行公司），或者其它类似的机制。有很多特定于 AUR 的包管理器能被用来从 AUR 里的 `PGKBUILD` 文件下载、编译、安装，下面我们来仔细看看怎么做。
|
||||
|
||||
##### 使用 pacman 和官方软件仓库
|
||||
|
||||
Arch 的主要包管理器：`pacman`，使用标识位而不是像 `yum` 或 `apt` 一样使用命令词。例如，要搜索一个包，你要用 `pacman -Ss` 。和 Linux 上别的命令一样，你可以找到 pacman 的手册页和在线帮助。`pacman` 大多数的命令都使用了同步（`-S`）这个标识位。例如：
|
||||
|
||||
```
|
||||
user@arch ~ $ pacman -Ss kate
|
||||
|
||||
extra/kate 18.04.2-2 (kde-applications kdebase)
|
||||
Advanced Text Editor
|
||||
extra/libkate 0.4.1-6 [installed]
|
||||
A karaoke and text codec for embedding in ogg
|
||||
extra/libtiger 0.3.4-5 [installed]
|
||||
A rendering library for Kate streams using Pango and Cairo
|
||||
extra/ttf-cheapskate 2.0-12
|
||||
TTFonts collection from dustimo.com
|
||||
community/haskell-cheapskate 0.1.1-100
|
||||
Experimental markdown processor.
|
||||
```
|
||||
|
||||
Arch 也使用和别的包管理器类似的软件仓库。在上面的输出中，搜索结果前面有标明它是从哪个仓库里搜索到的（这里是 `extra/` 和 `community/`）。同 Red Hat 和 Debian 系统一样，Arch 依靠用户将软件仓库的信息加入到一个特定的文件里：`/etc/pacman.conf`。下面的例子非常接近一个仓库系统。笔者还打开了 `[multilib]` 仓库来支持 Steam：
|
||||
|
||||
```
|
||||
[options]
|
||||
Architecture = auto
|
||||
|
||||
Color
|
||||
CheckSpace
|
||||
|
||||
SigLevel = Required DatabaseOptional
|
||||
LocalFileSigLevel = Optional
|
||||
|
||||
[core]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[extra]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[community]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[multilib]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
```
|
||||
|
||||
你也可以在 `pacman.conf` 里指定具体的 URL。这个功能可以用来确保在某一时刻所有的包来自一个确定的地方，比如，如果一个安装包存在严重的功能缺陷并且很不幸它恰好还有几个包依赖，你能及时回滚到一个安全点，如果你已经在 `pacman.conf` 里加入了具体的 URL 的话，你就用用这个命令降级你的系统。
|
||||
|
||||
```
|
||||
[core]
|
||||
Server=https://archive.archlinux.org/repos/2017/12/22/$repo/os/$arch
|
||||
```
|
||||
|
||||
和 Debian 系统一样，Arch 并不会自动更新它的本地仓库。你可以用下面的命令来刷新包管理器的数据库：
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Sy
|
||||
|
||||
:: Synchronizing package databases...
|
||||
core 130.2 KiB 851K/s 00:00 [##########################################################] 100%
|
||||
extra 1645.3 KiB 2.69M/s 00:01 [##########################################################] 100%
|
||||
community 4.5 MiB 2.27M/s 00:02 [##########################################################] 100%
|
||||
multilib is up to date
|
||||
```
|
||||
|
||||
你可以看到在上述的输出中，`pacman` 认为 multilib 包数据库是更新到最新状态的。如果你认为这个结果不正确的话，你可以强制运行刷新：`pacman -Syy`。如果你想升级你的整个系统的话（不包括从 AUR 安装的包），你可以运行 `pacman -Syu`：
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Syu
|
||||
|
||||
:: Synchronizing package databases...
|
||||
core is up to date
|
||||
extra is up to date
|
||||
community is up to date
|
||||
multilib is up to date
|
||||
:: Starting full system upgrade...
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (45) ceph-13.2.0-2 ceph-libs-13.2.0-2 debootstrap-1.0.105-1 guile-2.2.4-1 harfbuzz-1.8.2-1 harfbuzz-icu-1.8.2-1 haskell-aeson-1.3.1.1-20
|
||||
haskell-attoparsec-0.13.2.2-24 haskell-tagged-0.8.6-1 imagemagick-7.0.8.4-1 lib32-harfbuzz-1.8.2-1 lib32-libgusb-0.3.0-1 lib32-systemd-239.0-1
|
||||
libgit2-1:0.27.2-1 libinput-1.11.2-1 libmagick-7.0.8.4-1 libmagick6-6.9.10.4-1 libopenshot-0.2.0-1 libopenshot-audio-0.1.6-1 libosinfo-1.2.0-1
|
||||
libxfce4util-4.13.2-1 minetest-0.4.17.1-1 minetest-common-0.4.17.1-1 mlt-6.10.0-1 mlt-python-bindings-6.10.0-1 ndctl-61.1-1 netctl-1.17-1
|
||||
nodejs-10.6.0-1
|
||||
|
||||
Total Download Size: 2.66 MiB
|
||||
Total Installed Size: 879.15 MiB
|
||||
Net Upgrade Size: -365.27 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
在前面提到的降级系统的情景中，你可以运行 `pacman -Syyuu` 来强行降级系统。你必须重视这一点：虽然在大多数情况下这不会引起问题，但是这种可能性还是存在，即降级一个包或几个包将会引起级联传播的失败并会将你的系统处于不一致的状态（LCTT 译注：即系统进入无法正常使用的状态），请务必小心！
|
||||
|
||||
运行 `pacman -S kate` 来安装一个包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -S kate
|
||||
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (7) editorconfig-core-c-0.12.2-1 kactivities-5.47.0-1 kparts-5.47.0-1 ktexteditor-5.47.0-2 syntax-highlighting-5.47.0-1 threadweaver-5.47.0-1
|
||||
kate-18.04.2-2
|
||||
|
||||
Total Download Size: 10.94 MiB
|
||||
Total Installed Size: 38.91 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
你可以运行 `pacman -R kate` 来删除一个包。这将会只删除这个包自身而不会去删除它的依赖包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -S kate
|
||||
|
||||
checking dependencies...
|
||||
|
||||
Packages (1) kate-18.04.2-2
|
||||
|
||||
Total Removed Size: 20.30 MiB
|
||||
|
||||
:: Do you want to remove these packages? [Y/n]
|
||||
```
|
||||
|
||||
如果你想删除没有被其它包依赖的包，你可以运行 `pacman -Rs`：
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Rs kate
|
||||
|
||||
checking dependencies...
|
||||
|
||||
Packages (7) editorconfig-core-c-0.12.2-1 kactivities-5.47.0-1 kparts-5.47.0-1 ktexteditor-5.47.0-2 syntax-highlighting-5.47.0-1 threadweaver-5.47.0-1
|
||||
kate-18.04.2-2
|
||||
|
||||
Total Removed Size: 38.91 MiB
|
||||
|
||||
:: Do you want to remove these packages? [Y/n]
|
||||
```
|
||||
|
||||
在笔者看来，Pacman 是搜索一个指定实用程序中的包名的最齐全的工具。如上所示，YUM 和 APT 都依赖于“路径”去搜索到有用的结果，而 Pacman 则做了一些智能的猜测，它会去猜测你最有可能想搜索的包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Fs updatedb
|
||||
core/mlocate 0.26.git.20170220-1
|
||||
usr/bin/updatedb
|
||||
|
||||
user@arch ~ $ sudo pacman -Fs kate
|
||||
extra/kate 18.04.2-2
|
||||
usr/bin/kate
|
||||
```
|
||||
|
||||
##### 使用 AUR
|
||||
|
||||
有很多流行的 AUR 包管理器助手。其中 `yaourt` 和 `pacaur` 颇为流行。不过，这两个项目已经被 [Arch Wiki][21] 列为“不继续开发以及有已知的问题未解决”。因为这个原因，这里直接讨论 `aurman`，除了会搜索 AUR 以及包含几个有帮助的（其实很危险）的选项之外，它的工作机制和 `pacman` 极其类似。从 AUR 安装一个包将会初始化包维护者的构建脚本。你将会被要求输入几次授权以便让程序继续进行下去（为了简短起见，笔者截断了输出）。
|
||||
|
||||
```
|
||||
aurman -S telegram-desktop-bin
|
||||
~~ initializing aurman...
|
||||
~~ the following packages are neither in known repos nor in the aur
|
||||
...
|
||||
~~ calculating solutions...
|
||||
|
||||
:: The following 1 package(s) are getting updated:
|
||||
aur/telegram-desktop-bin 1.3.0-1 -> 1.3.9-1
|
||||
|
||||
?? Do you want to continue? Y/n: Y
|
||||
|
||||
~~ looking for new pkgbuilds and fetching them...
|
||||
Cloning into 'telegram-desktop-bin'...
|
||||
|
||||
remote: Counting objects: 301, done.
|
||||
remote: Compressing objects: 100% (152/152), done.
|
||||
remote: Total 301 (delta 161), reused 286 (delta 147)
|
||||
Receiving objects: 100% (301/301), 76.17 KiB | 639.00 KiB/s, done.
|
||||
Resolving deltas: 100% (161/161), done.
|
||||
?? Do you want to see the changes of telegram-desktop-bin? N/y: N
|
||||
|
||||
[sudo] password for user:
|
||||
|
||||
...
|
||||
==> Leaving fakeroot environment.
|
||||
==> Finished making: telegram-desktop-bin 1.3.9-1 (Thu 05 Jul 2018 11:22:02 AM EDT)
|
||||
==> Cleaning up...
|
||||
loading packages...
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (1) telegram-desktop-bin-1.3.9-1
|
||||
|
||||
Total Installed Size: 88.81 MiB
|
||||
Net Upgrade Size: 5.33 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
依照你所安装的包的复杂性程度的高低，有时你将会被要求给出进一步的输入，为了避免这些反复的输入，`aurman` 允许你使用 `--noconfirm` 和 `--noedit` 选项。这相当于说“接受所有的预定设置，并相信包管理器不会干坏事”。**使用这两个选项时请务必小心！！**，虽然这些选项本身不太会破坏你的系统，你也不能盲目的接受他人的脚本程序。
|
||||
|
||||
### 总结
|
||||
|
||||
这篇文章当然只能触及包管理器的皮毛。还有很多别的包管理器笔者没有在这篇文章里谈及。有些 Linux 发布版，如 Ubuntu 或 Elementary OS，已经在图形版的包管理器的开发上有了长远的进展。
|
||||
|
||||
如果你对包管理器的更高级功能有进一步的兴趣，请在评论区留言，笔者很乐意进一步的写一写相关的文章。
|
||||
|
||||
### 附录
|
||||
|
||||
```
|
||||
# search for packages
|
||||
yum search <package>
|
||||
dnf search <package>
|
||||
zypper search <package>
|
||||
apt-cache search <package>
|
||||
apt search <package>
|
||||
pacman -Ss <package>
|
||||
|
||||
# install packages
|
||||
yum install <package>
|
||||
dnf install <package>
|
||||
zypper install <package>
|
||||
apt-get install <package>
|
||||
apt install <package>
|
||||
pacman -Ss <package>
|
||||
|
||||
# update package database, not required by yum, dnf and zypper
|
||||
apt-get update
|
||||
apt update
|
||||
pacman -Sy
|
||||
|
||||
# update all system packages
|
||||
yum update
|
||||
dnf update
|
||||
zypper update
|
||||
apt-get upgrade
|
||||
apt upgrade
|
||||
pacman -Su
|
||||
|
||||
# remove an installed package
|
||||
yum remove <package>
|
||||
dnf remove <package>
|
||||
apt-get remove <package>
|
||||
apt remove <package>
|
||||
pacman -R <package>
|
||||
pacman -Rs <package>
|
||||
|
||||
# search for the package name containing specific file or folder
|
||||
yum whatprovides *<binary>
|
||||
dnf whatprovides *<binary>
|
||||
zypper what-provides <binary>
|
||||
zypper search --provides <binary>
|
||||
apt-file search <binary>
|
||||
pacman -Sf <binary>
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/7/evolution-package-managers
|
||||
|
||||
作者：[Steve Ovens][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[DavidChenLiang](https://github.com/davidchenliang)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/stratusss
|
||||
[1]:https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures
|
||||
[2]:https://en.wikipedia.org/wiki/Yum_(software)
|
||||
[3]:https://fedoraproject.org/wiki/DNF
|
||||
[4]:https://en.wikipedia.org/wiki/Rpm_(software)
|
||||
[5]:https://en.wikipedia.org/wiki/Yellow_Dog_Linux
|
||||
[6]:https://searchdatacenter.techtarget.com/definition/Yellowdog-Updater-Modified-YUM
|
||||
[7]:https://en.wikipedia.org/wiki/DNF_(software)
|
||||
[8]:https://en.opensuse.org/Portal:Zypper
|
||||
[9]:https://www.suse.com/
|
||||
[10]:https://www.opensuse.org/
|
||||
[11]:https://en.wikipedia.org/wiki/MeeGo
|
||||
[12]:https://sailfishos.org/
|
||||
[13]:https://www.tizen.org/
|
||||
[14]:https://en.wikipedia.org/wiki/YaST
|
||||
[15]:https://en.wikipedia.org/wiki/APT_(Debian)
|
||||
[16]:https://www.archlinux.org/
|
||||
[17]:https://wiki.archlinux.org/index.php/pacman
|
||||
[18]:https://wiki.archlinux.org/index.php/Arch_Build_System
|
||||
[19]:https://aur.archlinux.org/
|
||||
[20]:https://hub.docker.com/
|
||||
[21]:https://wiki.archlinux.org/index.php/AUR_helpers#Discontinued_or_problematic
|
||||
@ -0,0 +1,46 @@
|
||||
Open Source Networking Jobs: A Hotbed of Innovation and Opportunities
|
||||
======
|
||||
|
||||
|
||||
|
||||
As global economies move ever closer to a digital future, companies and organizations in every industry vertical are grappling with how to further integrate and deploy technology throughout their business and operations. While Enterprise IT largely led the way, the advantages and lessons learned are now starting to be applied across the board. While the national unemployment rate stands at 4.1%, the overall unemployment rate for tech professionals hit 1.9% in April and the future for open source jobs looks particularly bright. I work in the open source networking space and the innovations and opportunities I’m witnessing are transforming the way the world communicates.
|
||||
|
||||
Once a slower moving industry, the networking ecosystem of today -- made up of network operators, vendors, systems integrators, and developers -- is now embracing open source software and is shifting significantly towards virtualization and software defined networks running on commodity hardware. In fact, nearly 70% of global mobile subscribers are represented by network operator members of [LF Networking][1], an initiative working to harmonize projects that makes up the open networking stack and adjacent technologies.
|
||||
|
||||
### Demand for Skills
|
||||
|
||||
Developers and sysadmins working in this space are embracing cloud native and DevOps approaches and methods to develop new use cases and tackle the most pressing industry challenges. Focus areas like containers and edge computing are red hot and the demand for developers and sysadmins who can integrate, collaborate, and innovate in this space is exploding.
|
||||
|
||||
Open source and Linux makes this all possible, and per the recently published [2018 Open Source Jobs Report][2], fully 80% of hiring managers are looking for people with Linux skills **while 46% are looking to recruit in the networking area and a roughly equal equal percentage cite “Networking” as a technology most affecting their hiring decisions.**
|
||||
|
||||
Developers are the most sought-after position, with 72% of hiring managers looking for them, followed by DevOps skills (59%), engineers (57%) and sysadmins (49%). The report also measures the incredible growth in demand for containers skills which matches what we’re seeing in the networking space with the creation of cloud native virtual functions (CNFs) and the proliferation of Continuous Integration / Continuous Deployment approaches such as the [XCI initiative][3] in the OPNFV.
|
||||
|
||||
### Get Started
|
||||
|
||||
The good news for job seekers in that there are plenty of onramps into open source including the free [Introduction to Linux][4] course. Multiple certifications are mandatory for the top jobs so I encourage you to explore the range of training opportunities out there. Specific to networking, check out these new training courses in the [OPNFV][5] and [ONAP][6] projects, as well as this [introduction to open source networking technologies][7].
|
||||
|
||||
If you haven’t done so already, download the [2018 Open Source Jobs Report][2] now for more insights and plot your course through the wide world of open source technology to the exciting career that waits for you on the other side!
|
||||
|
||||
[Download the complete Open Source Jobs Report][8]now and[learn more about Linux certification here.][9]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/os-jobs-report/2018/7/open-source-networking-jobs-hotbed-innovation-and-opportunities
|
||||
|
||||
作者：[Brandon Wick][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.linux.com/users/brandon-wick
|
||||
[1]:https://www.lfnetworking.org/
|
||||
[2]:https://www.linuxfoundation.org/publications/2018/06/open-source-jobs-report-2018/
|
||||
[3]:https://docs.opnfv.org/en/latest/submodules/releng-xci/docs/xci-overview.html
|
||||
[4]:https://www.edx.org/course/introduction-linux-linuxfoundationx-lfs101x-1
|
||||
[5]:https://training.linuxfoundation.org/training/opnfv-fundamentals/
|
||||
[6]:https://training.linuxfoundation.org/training/onap-fundamentals/
|
||||
[7]:https://www.edx.org/course/introduction-to-software-defined-networking-technologies
|
||||
[8]:https://www.linuxfoundation.org/publications/open-source-jobs-report-2018/
|
||||
[9]:https://training.linuxfoundation.org/certification
|
||||
@ -0,0 +1,71 @@
|
||||
Mixing software development roles produces great results
|
||||
======
|
||||
|
||||
|
||||
|
||||
Most open source communities don’t have a lot of formal roles. There are certainly people who help with sysadmin tasks, testing, writing documentation, and translating or developing code. But people in open source communities typically move among different roles, often fulfilling several at once.
|
||||
|
||||
In contrast, team members at most traditional companies have defined roles, working on documentation, support, QA, and in other areas.
|
||||
|
||||
Why do open source communities take a shared-role approach, and more importantly, how does this way of collaborating affect products and customers?
|
||||
|
||||
[Nextcloud][1] has adopted this community-style practice of mixing roles, and we see large benefits for our customers and our users.
|
||||
|
||||
### 1\. Better product testing
|
||||
|
||||
Testing is a difficult job, as any tester can tell you. You need to understand the products engineers develop, and you need to devise test plans, execute them, and return the results to the developers. When that process is done, the developer makes changes, and you repeat the process, going back-and-forth as many times as necessary until the job is done.
|
||||
|
||||
In a community, contributors typically feel responsible for the projects they develop, so they test and document them extensively before handing them to users. Users close to the project often help test, translate, and write documentation in collaboration with developers. This creates a much tighter, faster feedback loop, speeding up development and improving quality.
|
||||
|
||||
When developers continuously confront the results of their work, it encourages them to write in a way that minimizes testing and debugging. Automated testing is an important element in development, and the feedback loop ensures that it is done right: Developers are organically motivated to automate what should be automated—no more and no less. Sure, they might _want_ others to do more testing or test automation, but when testing is the right thing to do, they do it. Moreover, they review each others' code because they know that issues tend to come back bite them later.
|
||||
|
||||
So, while I won't argue that it's better to forgo dedicated testers, certainly in a project without community volunteers who test, testers should be developers and closely embedded in the development team. The result? Customers get a product that was tested and developed by people who are 100% motivated to ensure that it is stable and reliable.
|
||||
|
||||
### 2\. Close alignment between development and customer needs
|
||||
|
||||
It is extraordinarily difficult to align product development with customer needs. Every customer has their own unique needs, there are long- and short-term factors to consider—and of course, as a company, you have ideas on where you want to go. How do you integrate all these ideas and visions?
|
||||
|
||||
Companies typically create roles like product management, support, QA, and others, which are separate from engineering and product development. The idea behind this is that people do best when they specialize, and engineers shouldn't be bothered with "simple" tasks like testing or support.
|
||||
|
||||
In effect, this role separation is a cost-cutting measure. It enables management to micromanage and feel more in control as they can simply order product management, for example, to prioritize items on the roadmap. (It also creates more meetings!)
|
||||
|
||||
In communities, on the other hand, "those who do the work decide." Developers are often also users (or are paid by users), so they align with users’ needs naturally. When users help with testing (as described above), developers work with them constantly, so both sides fully understand what is possible and what is needed.
|
||||
|
||||
This open way of working closely aligns users and projects. Without management interference and overhead, users' most pressing needs can be quickly met because engineers already intimately understand them.
|
||||
|
||||
At Nextcloud, customers never need to explain things twice or rely on a junior support team member to accurately communicate issues to an engineer. Our engineers continuously calibrate their priorities based on real customer needs. Meanwhile, long-term goals are set collaboratively, based on a deep knowledge of our customers.
|
||||
|
||||
### 3\. The best support
|
||||
|
||||
Unlike proprietary or [open core][2] vendors, open source vendors have a powerful incentive to offer the best possible support: It is a key differentiator from other companies in their ecosystem.
|
||||
|
||||
Why is the driving force behind a project—think [Collabora][3] behind [LibreOffice][4], [The Qt Company][5] behind [Qt][6], or [Red Hat][7] behind [RHEL][8]—the best source of customer support?
|
||||
|
||||
Direct access to engineers, of course. Rather than walling off support from engineering, many of these companies offer customers access to engineers' expertise. This helps ensure that customers always get the best answers as quickly as possible. While some engineers may spend more time than others on support, the entire engineering team plays a role in customer success. Proprietary vendors might provide customers a dedicated on-site engineer for a considerable cost, for example, but an open source company like [OpenNMS][9] offers that same level of service in your support contract—even if you’re not a Fortune 500 customer.
|
||||
|
||||
There's another benefit, which relates back to testing and customer alignment: Sharing roles ensures that engineers deal with customer issues and wishes daily, which motivates them to fix the most common problems quickly. They also tend to build extra tools and features to save customers from asking.
|
||||
|
||||
Put simply, folding QA, support, product management, and other engineering roles into one team ensures that the three famous virtues of great developers—[laziness, impatience, and hubris][10]—closely align with customers.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/mixing-roles-engineering
|
||||
|
||||
作者：[Jos Poortvliet][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/jospoortvliet
|
||||
[1]:https://nextcloud.com/
|
||||
[2]:https://en.wikipedia.org/wiki/Open_core
|
||||
[3]:https://www.collaboraoffice.com/
|
||||
[4]:https://www.libreoffice.org/
|
||||
[5]:https://www.qt.io/
|
||||
[6]:https://www.qt.io/developers/
|
||||
[7]:https://www.redhat.com/en
|
||||
[8]:https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux
|
||||
[9]:https://www.opennms.org/en
|
||||
[10]:http://threevirtues.com/
|
||||
@ -0,0 +1,60 @@
|
||||
OERu makes a college education affordable
|
||||
======
|
||||
|
||||
|
||||
|
||||
Open, higher education courses are a boon to adults who don’t have the time, money, or confidence to enroll in traditional college courses but want to further their education for work or personal satisfaction. [OERu][1] is a great option for these learners. It allows people to take courses assembled by accredited colleges and universities for free, using open textbooks, and pay for assessment only when (and if) they want to apply for formal academic credit.
|
||||
|
||||
I spoke with [Dave Lane][2], open source technologist at the [Open Education Resource Foundation][3], which is OERu’s parent organization, to learn more about the program. The OER Foundation is a nonprofit organization hosted by [Otago Polytechnic][4] in Dunedin, New Zealand. It partners with organizations around the globe to provide leadership, networking, and support to help advance [open education principles][5].
|
||||
|
||||
OERu is one of the foundation's flagship projects. (The other is [WikiEducator][6], a community of educators collaboratively developing open source materials.) OERu was conceived in 2011, two years after the foundation’s launch, with representatives from educational institutions around the world.
|
||||
|
||||
Its network "is made up of tertiary educational institutions in five continents working together to democratize tertiary education and its availability for those who cannot afford (or cannot find a seat in) tertiary education," Dave says. Some of OERu’s educational partners include UTaz (Australia), Thompson River University (Canada), North-West University or National Open University (ZA and Nigeria in Africa, respectively), and the University of the Highlands and Islands (Scotland in the UK). Funding is provided by the [William and Flora Hewlett Foundation][7]. These institutions have worked out the complexity associated with transferring academic credits within the network and across the different educational cultures, accreditation boards, and educational review committees.
|
||||
|
||||
### How it works
|
||||
|
||||
The primary requirements for taking OERu courses are fluency in English (which is the primary teaching language) and having a computer with internet access. To start learning, peruse the [list of courses][8], click the title of the course you want to take, and click “Start Learning” to complete any registration details (different courses have different requirements).
|
||||
|
||||
Once you complete a course, you can take an assessment that may qualify you for college-level course credit. While there’s no cost to take a course, each partner institution charges fees for administering assessments—but they are far less expensive than traditional college tuition and fees.
|
||||
|
||||
In March 2018, OERu launched a [Certificate Higher Education Business][9] (CertHE), a one-year program that the organization calls its [first year of study][10], which is "equivalent to the first year of a bachelor's degree." CertHE “is an introductory level qualification in business and management studies which provides a general overview for a possible career in business across a wide range of sectors and industries.” Although CertHE assessment costs vary, it’s likely that the first full year of study will be US$ 2,500, a significant cost savings for students.
|
||||
|
||||
OERu is adding courses and looking for ways to expand the model to eventually offer full baccalaureate degrees and possibly even graduate degrees at much lower cost than a traditional degree program.
|
||||
|
||||
### Open source technologist's background
|
||||
|
||||
Dave didn’t set out to work in IT or live and work in New Zealand. He grew up in the United States and earned his master’s degree in mechanical engineering from the University of Washington. Fresh out of graduate school, he moved to New Zealand to take a position as a research scientist at a government-funded [Crown Research Institute][11] to improve the efficiency of the country’s forest industry.
|
||||
|
||||
IT and open technologies were important parts of getting his job done. "The image processing and photogrammetry software I developed … was built on Linux, entirely using open source math (C/C++) and interface libraries (Qt)," he says. "The source material for my advanced photogrammetric algorithms was US Geological Survey scientist papers from the 1950s-60s, all publicly available."
|
||||
|
||||
His frustration with the low quality of IT systems in the outlying offices led him to assume the role of "ad hoc IT manager" using "100% open source software," he says, which delighted his colleagues but frustrated the fulltime IT staff in the main office.
|
||||
|
||||
After four years of working for the government, he founded a company called Egressive to build Linux-based server systems for small businesses in the Christchurch area. Egressive became a successful small business IT provider, specializing in free and open source software, web development and hosting, systems integration, and outsourced sysadmin services. After selling the business, he joined the OER Foundation’s staff in 2015. In addition to working on the WikiEducator.org and OERu projects, he develops [open source collaboration][12] and teaching tools for the foundation.
|
||||
|
||||
If you're interested in learning more about the OER Foundation, OERu, open source technology, and Dave's work, take a look at [his blog][13].
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/oeru-courses
|
||||
|
||||
作者：[João Trindade][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.flickr.com/photos/joao_trindade/4362409183
|
||||
[1]:https://oeru.org/
|
||||
[2]:https://www.linkedin.com/in/davelanenz/
|
||||
[3]:http://wikieducator.org/OERF:Home
|
||||
[4]:https://www.op.ac.nz/
|
||||
[5]:https://oeru.org/how-it-works/
|
||||
[6]:http://wikieducator.org/
|
||||
[7]:https://hewlett.org/
|
||||
[8]:https://oeru.org/courses/
|
||||
[9]:https://oeru.org/certhe-business/
|
||||
[10]:https://oeru.org/qualifications/
|
||||
[11]:https://en.wikipedia.org/wiki/Crown_Research_Institute
|
||||
[12]:https://tech.oeru.org/many-simple-tools-loosely-coupled
|
||||
[13]:https://tech.oeru.org/blog/1
|
||||
@ -0,0 +1,623 @@
|
||||
A Word from The Beegoist – Richard Kenneth Eng – Medium
|
||||
======
|
||||
I like the [Go programming language][22]. I sought to use Go to write web applications. To this end, I examined two of the “full stack” web frameworks available to Go developers (aka “Gophers”): [Beego][23] and [Revel][24].
|
||||
|
||||
The reason I looked for full stack was because of my prior experience with [web2py][25], a Python-based framework with extraordinary capability that was also [deliciously easy to get started and be highly productive in][26]. (I also cut my teeth on Smalltalk-based [Seaside][27], which has the same qualities.) In my opinion, full stack is the only way to go because developers should not waste time and effort on the minutiae of tool configuration and setup. The focus should be almost entirely on writing your application.
|
||||
|
||||
Between Beego and Revel, I chose the former. It seemed to be more mature and better documented. It also had a built-in [ORM][28].
|
||||
|
||||
To be sure, Beego isn’t as easy and productive as web2py, but I believe in Go, so it is worth the effort to give Beego my best shot. To get started with Beego, I needed a project, a useful exercise that covered all the bases, such as database management, CSS styling, email capability, form validation, etc., and also provided a useful end product.
|
||||
|
||||
The project I selected was a user account management component for web applications. All of my previous applications required user registration/login, and Beego did not appear to have anything like that available.
|
||||
|
||||
Now that I’ve completed the project, I believe it would be an excellent foundation for a Beego tutorial. I do not pretend that the code is optimal, nor do I pretend that it is bug-free, but if there are any bugs, it would be a good exercise for a novice to resolve them.
|
||||
|
||||
The inspiration for this tutorial arose from my failure to find good, thorough tutorials when I first started learning Beego. There is one 2-part tutorial that is often mentioned, but I found Part 2 sorely lacking. Throwing source code at you for you to figure out on your own is no way to teach. Thus, I wanted to offer my take on a tutorial. Only history will determine whether it was successful.
|
||||
|
||||
So, without further ado, let’s begin. The word is “Go!”
|
||||
|
||||
### Basic Assumptions
|
||||
|
||||
You have some familiarity with the Go language. I highly recommend you follow this [Go tutorial][1].
|
||||
|
||||
You’ve installed [Go][2] and [Beego][3] on your computer. There are plenty of good online resources to help you here (for [example][4]). It’s really quite easy.
|
||||
|
||||
You have basic knowledge of CSS, HTML, and databases. You have at least one database package installed on your computer such as [MySQL][5] (Community Edition) or [SQLite][6]. I have SQLite because it’s much easier to use.
|
||||
|
||||
You have some experience writing software; basic skills are assumed. If you studied computer programming in school, then you’re off to a good start.
|
||||
|
||||
You will be using your favourite programming editor in conjunction with the command line. I use [LiteIDE][7] (on the Mac), but I can suggest alternatives such as [TextMate][8] for the Mac, [Notepad++][9] for Windows, and [vim][10] for Linux.
|
||||
|
||||
These basic assumptions define the target audience for the tutorial. If you’re a programming veteran, though, you’ll breeze through it and hopefully gain much useful knowledge, as well.
|
||||
|
||||
### Creating the Project
|
||||
|
||||
First, we must create a Beego project. We’ll call it ‘[ACME][11]’. From the command line, change directory (cd) to $GOPATH/src and enter:
|
||||
```
|
||||
$ bee new acme
|
||||
|
||||
```
|
||||
|
||||
The following directory structure will be created:
|
||||
```
|
||||
acme
|
||||
....conf
|
||||
....controllers
|
||||
....models
|
||||
....routers
|
||||
....static
|
||||
........css
|
||||
........img
|
||||
........js
|
||||
....tests
|
||||
....views
|
||||
|
||||
```
|
||||
|
||||
Note that Beego is a MVC framework (Model/View/Controller), which means that your application will be separated into three general sections. Model refers to the internal database structure of your application. View is all about how your application looks on the computer screen; in our case, this includes HTML and CSS code. And Controller is where you have your business logic and user interactions.
|
||||
|
||||
You can immediately compile and run your application by changing directory (cd acme) and typing:
|
||||
```
|
||||
$ bee run
|
||||
|
||||
```
|
||||
|
||||
In your browser, go to <http://localhost:8080> to see the running application. It doesn’t do anything fancy right now; it simply greets you. But upon this foundation, we shall raise an impressive edifice.
|
||||
|
||||
### The Source Code
|
||||
|
||||
To follow along, you may [download the source code][12] for this tutorial. Cd to $GOPATH/src and unzip the file. [When you download the source, the filename that Github uses is ‘acme-master’. You must change it to ‘acme’.]
|
||||
|
||||
### Program Design
|
||||
|
||||
The user account management component provides the following functionality:
|
||||
|
||||
1. User registration (account creation)
|
||||
2. Account verification (via email)
|
||||
3. Login (create a session)
|
||||
4. Logout (delete the session)
|
||||
5. User profile (can change name, email, or password)
|
||||
6. Remove user account
|
||||
|
||||
|
||||
|
||||
The essence of a web application is the mapping of URLs (webpages) to the server functions that will process the HTTP requests. This mapping is what generates the work flow in the application. In Beego, the mapping is defined within the ‘router’. Here’s the code for our router (look at router.go in the ‘routers’ directory):
|
||||
```
|
||||
beego.Router("/home", &controllers.MainController{})
|
||||
beego.Router("/user/login/:back", &controllers.MainController{}, "get,post:Login")
|
||||
beego.Router("/user/logout", &controllers.MainController{}, "get:Logout")
|
||||
beego.Router("/user/register", &controllers.MainController{}, "get,post:Register")
|
||||
beego.Router("/user/profile", &controllers.MainController{}, "get,post:Profile")
|
||||
beego.Router("/user/verify/:uuid({[0-9A-F]{8}-[0-9A-F]{4}-4[0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}})", &controllers.MainController{}, "get:Verify")
|
||||
beego.Router("/user/remove", &controllers.MainController{}, "get,post:Remove")
|
||||
beego.Router("/notice", &controllers.MainController{}, "get:Notice")
|
||||
|
||||
```
|
||||
|
||||
For example, in the line for ‘login’, “get,post:Login” says that both the GET and POST operations are handled by the ‘Login’ function. The ‘:back’ is a request parameter; in this case, it tells us what page to return to after successful login.
|
||||
|
||||
In the line for ‘verify’, the ‘:uuid’ is a request parameter that must match the [regular expression][13] for a Version 4 UUID. The GET operation is handled by the ‘Verify’ function.
|
||||
|
||||
More on this when we talk about controllers.
|
||||
|
||||
Note that I’ve added ‘/home’ to the first line in the router (it was originally ‘/’). This makes it convenient to go to the home page, which we often do in our application.
|
||||
|
||||
### Model
|
||||
|
||||
The database model for a user account is represented by the following struct:
|
||||
```
|
||||
package models
|
||||
|
||||
```
|
||||
```
|
||||
import (
|
||||
"github.com/astaxie/beego/orm"
|
||||
"time"
|
||||
)
|
||||
|
||||
```
|
||||
```
|
||||
type AuthUser struct {
|
||||
Id int
|
||||
First string
|
||||
Last string
|
||||
Email string `orm:"unique"`
|
||||
Password string
|
||||
Reg_key string
|
||||
Reg_date time.Time `orm:"auto_now_add;type(datetime)"`
|
||||
}
|
||||
|
||||
```
|
||||
```
|
||||
func init() {
|
||||
orm.RegisterModel(new(AuthUser))
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
Place this in models.go in the ‘models’ directory. Ignore the init() for the time being.
|
||||
|
||||
‘Id’ is the primary key which is auto-incremented in the database. We also have ‘First’ and ‘Last’ names. ‘Password’ contains the hexadecimal representation of the [PBKDF2 hash][14] of the plaintext password.
|
||||
|
||||
‘Reg_key’ contains the [UUID][15] string that is used for account verification (via email). ‘Reg_date’ is the timestamp indicating the time of registration.
|
||||
|
||||
The funny-looking string literals associated with both ‘Email’ and ‘Reg_date’ are used to tell the database the special requirements of these fields. ‘Email’ must be a unique key. ‘Reg_date’ will be automatically assigned the date and time of database insertion.
|
||||
|
||||
By the way, don’t be scared of the PBKDF2 and UUID references. PBKDF2 is simply a way to securely store a user’s password in the database. A UUID is a unique identifier that can be used to ensure the identity of the user for verification purposes.
|
||||
|
||||
### View
|
||||
|
||||
For our CSS template design, I’ve chosen the [Stardust][16] theme (pictured at the start of this article). We will use its index.html as a basis for the view layout.
|
||||
|
||||
Place the appropriate files from the Stardust theme into the ‘css’ and ‘img’ directories of ‘static’ directory. The link statement in the header of index.html must be amended to:
|
||||
```
|
||||
<link href="/static/css/default.css" rel="stylesheet" type="text/css" />
|
||||
|
||||
```
|
||||
|
||||
And all references to image gifs and jpegs in index.html and default.css must point to ‘/static/img/’.
|
||||
|
||||
The view layout contains a header section, a footer section, a sidebar section, and the central section where most of the action will take place. We will be using Go’s templating facility which allows us to replace embedded codes, signified by ‘{{‘ and ‘}}’, with actual HTML. Here’s our basic-layout.tpl (.tpl for ‘template’):
|
||||
```
|
||||
{{.Header}}
|
||||
{{.LayoutContent}}
|
||||
{{.Sidebar}}
|
||||
{{.Footer}}
|
||||
|
||||
```
|
||||
|
||||
Since every webpage in our application will need to adhere to this basic layout, we need a common method to set it up (look at default.go):
|
||||
```
|
||||
func (this *MainController) activeContent(view string) {
|
||||
this.Layout = "basic-layout.tpl"
|
||||
this.LayoutSections = make(map[string]string)
|
||||
this.LayoutSections["Header"] = "header.tpl"
|
||||
this.LayoutSections["Sidebar"] = "sidebar.tpl"
|
||||
this.LayoutSections["Footer"] = "footer.tpl"
|
||||
this.TplNames = view + ".tpl"
|
||||
|
||||
```
|
||||
```
|
||||
sess := this.GetSession("acme")
|
||||
if sess != nil {
|
||||
this.Data["InSession"] = 1 // for login bar in header.tpl
|
||||
m := sess.(map[string]interface{})
|
||||
this.Data["First"] = m["first"]
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
The template parameters, such as ‘.Sidebar’, correspond to the keys used in the LayoutSections map. ‘.LayoutContent’ is a special, implicit template parameter. We’ll get to the GetSession stuff further below.
|
||||
|
||||
Of course, we need to create the various template files (such as footer.tpl) in the ‘views’ directory. From index.html, we can carve out the header section for header.tpl:
|
||||
```
|
||||
<!DOCTYPE html>
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
|
||||
<title>StarDust by Free Css Templates</title>
|
||||
<meta name="keywords" content="" />
|
||||
<meta name="description" content="" />
|
||||
<link href="/static/css/default.css" rel="stylesheet" type="text/css" />
|
||||
</head>
|
||||
|
||||
```
|
||||
```
|
||||
<body>
|
||||
<!-- start header -->
|
||||
<div id="header-bg">
|
||||
<div id="header">
|
||||
<div align="right">{{if .InSession}}
|
||||
Welcome, {{.First}} [<a href="http://localhost:8080/logout">Logout</a>|<a href="http://localhost:8080/profile">Profile</a>]
|
||||
{{else}}
|
||||
[<a href="http://localhost:8080/login/home">Login</a>]
|
||||
{{end}}
|
||||
</div>
|
||||
<div id="logo">
|
||||
<h1><a href="#">StarDust<sup></sup></a></h1>
|
||||
<h2>Designed by FreeCSSTemplates</h2>
|
||||
</div>
|
||||
<div id="menu">
|
||||
<ul>
|
||||
<li class="active"><a href="http://localhost:8080/home">home</a></li>
|
||||
<li><a href="#">photos</a></li>
|
||||
<li><a href="#">about</a></li>
|
||||
<li><a href="#">links</a></li>
|
||||
<li><a href="#">contact </a></li>
|
||||
</ul>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
<!-- end header -->
|
||||
<!-- start page -->
|
||||
<div id="page">
|
||||
|
||||
```
|
||||
|
||||
I leave it as an exercise for you to carve out the sections for sidebar.tpl and footer.tpl.
|
||||
|
||||
Note the lines in bold. I added them to facilitate a “login bar” at the top of every webpage. Once you’ve logged into the application, you will see the bar as so:
|
||||
|
||||
![][17]
|
||||
|
||||
This login bar works in conjunction with the GetSession code snippet we saw in activeContent(). The logic is, if the user is logged in (ie, there is a non-nil session), then we set the InSession parameter to a value (any value), which tells the templating engine to use the “Welcome” bar instead of “Login”. We also extract the user’s first name from the session so that we can present the friendly affectation “Welcome, Richard”.
|
||||
|
||||
The home page, represented by index.tpl, uses the following snippet from index.html:
|
||||
```
|
||||
<!-- start content -->
|
||||
<div id="content">
|
||||
<div class="post">
|
||||
<h1 class="title">Welcome to StarDust</h1>
|
||||
// to save space, I won't enter the remainder
|
||||
// of the snippet
|
||||
</div>
|
||||
<!-- end content -->
|
||||
|
||||
```
|
||||
|
||||
#### Special Note
|
||||
|
||||
The template files for the user module reside in the ‘user’ directory within ‘views’, just to keep things tidy. So, for example, the call to activeContent() for login is:
|
||||
```
|
||||
this.activeContent("user/login")
|
||||
|
||||
```
|
||||
|
||||
### Controller
|
||||
|
||||
A controller handles requests by handing them off to the appropriate function or ‘method’. We only have one controller for our application and it’s defined in default.go. The default method Get() for handling a GET operation is associated with our home page:
|
||||
```
|
||||
func (this *MainController) Get() {
|
||||
this.activeContent("index")
|
||||
|
||||
```
|
||||
```
|
||||
//bin //boot //dev //etc //home //lib //lib64 //media //mnt //opt //proc //root //run //sbin //speedup //srv //sys //tmp //usr //var This page requires login
|
||||
sess := this.GetSession("acme")
|
||||
if sess == nil {
|
||||
this.Redirect("/user/login/home", 302)
|
||||
return
|
||||
}
|
||||
m := sess.(map[string]interface{})
|
||||
fmt.Println("username is", m["username"])
|
||||
fmt.Println("logged in at", m["timestamp"])
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
I’ve made login a requirement for accessing this page. Logging in means creating a session, which by default expires after 3600 seconds of inactivity. A session is typically maintained on the client side by a ‘cookie’.
|
||||
|
||||
In order to support sessions in the application, the ‘SessionOn’ flag must be set to true. There are two ways to do this:
|
||||
|
||||
1. Insert ‘beego.SessionOn = true’ in the main program, main.go.
|
||||
2. Insert ‘sessionon = true’ in the configuration file, app.conf, which can be found in the ‘conf’ directory.
|
||||
|
||||
|
||||
|
||||
I chose #1. (But note that I used the configuration file to set ‘EnableAdmin’ to true: ‘enableadmin = true’. EnableAdmin allows you to use the Supervisor Module in Beego that keeps track of CPU, memory, Garbage Collector, threads, etc., via port 8088: <http://localhost:8088>.)
|
||||
|
||||
#### The Main Program
|
||||
|
||||
The main program is also where we initialize the database to be used with the ORM (Object Relational Mapping) component. ORM makes it more convenient to perform database activities within our application. The main program’s init():
|
||||
```
|
||||
func init() {
|
||||
orm.RegisterDriver("sqlite", orm.DR_Sqlite)
|
||||
orm.RegisterDataBase("default", "sqlite3", "acme.db")
|
||||
name := "default"
|
||||
force := false
|
||||
verbose := false
|
||||
err := orm.RunSyncdb(name, force, verbose)
|
||||
if err != nil {
|
||||
fmt.Println(err)
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
To use SQLite, we must import ‘go-sqlite3', which can be installed with the command:
|
||||
```
|
||||
$ go get github.com/mattn/go-sqlite3
|
||||
|
||||
```
|
||||
|
||||
As you can see in the code snippet, the SQLite driver must be registered and ‘acme.db’ must be registered as our SQLite database.
|
||||
|
||||
Recall in models.go, there was an init() function:
|
||||
```
|
||||
func init() {
|
||||
orm.RegisterModel(new(AuthUser))
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
The database model has to be registered so that the appropriate table can be generated. To ensure that this init() function is executed, you must import ‘models’ without actually using it within the main program, as follows:
|
||||
```
|
||||
import _ "acme/models"
|
||||
|
||||
```
|
||||
|
||||
RunSyncdb() is used to autogenerate the tables when you start the program. (This is very handy for creating the database tables without having to **manually** do it in the database command line utility.) If you set ‘force’ to true, it will drop any existing tables and recreate them.
|
||||
|
||||
#### The User Module
|
||||
|
||||
User.go contains all the methods for handling login, registration, profile, etc. There are several third-party packages we need to import; they provide support for email, PBKDF2, and UUID. But first we must get them into our project…
|
||||
```
|
||||
$ go get github.com/alexcesaro/mail/gomail
|
||||
$ go get github.com/twinj/uuid
|
||||
|
||||
```
|
||||
|
||||
I originally got **github.com/gokyle/pbkdf2** , but this package was pulled from Github, so you can no longer get it. I’ve incorporated this package into my source under the ‘utilities’ folder, and the import is:
|
||||
```
|
||||
import pk "acme/utilities/pbkdf2"
|
||||
|
||||
```
|
||||
|
||||
The ‘pk’ is a convenient alias so that I don’t have to type the rather unwieldy ‘pbkdf2'.
|
||||
|
||||
#### ORM
|
||||
|
||||
It’s pretty straightforward to use ORM. The basic pattern is to create an ORM object, specify the ‘default’ database, and select which ORM operation you want, eg,
|
||||
```
|
||||
o := orm.NewOrm()
|
||||
o.Using("default")
|
||||
err := o.Insert(&user) // or
|
||||
err := o.Read(&user, "Email") // or
|
||||
err := o.Update(&user) // or
|
||||
err := o.Delete(&user)
|
||||
|
||||
```
|
||||
|
||||
#### Flash
|
||||
|
||||
By the way, Beego provides a way to present notifications on your webpage through the use of ‘flash’. Basically, you create a ‘flash’ object, give it your notification message, store the flash in the controller, and then retrieve the message in the template file, eg,
|
||||
```
|
||||
flash := beego.NewFlash()
|
||||
flash.Error("You've goofed!") // or
|
||||
flash.Notice("Well done!")
|
||||
flash.Store(&this.Controller)
|
||||
|
||||
```
|
||||
|
||||
And in your template file, reference the Error flash with:
|
||||
```
|
||||
{{if .flash.error}}
|
||||
<h3>{{.flash.error}}</h3>
|
||||
|
||||
{{end}}
|
||||
|
||||
```
|
||||
|
||||
#### Form Validation
|
||||
|
||||
Once the user posts a request (by pressing the Submit button, for example), our handler must extract and validate the form input. So, first, check that we have a POST operation:
|
||||
```
|
||||
if this.Ctx.Input.Method() == "POST" {
|
||||
|
||||
```
|
||||
|
||||
Let’s get a form element, say, email:
|
||||
```
|
||||
email := this.GetString("email")
|
||||
|
||||
```
|
||||
|
||||
The string “email” is the same as in the HTML form:
|
||||
```
|
||||
<input name="email" type="text" />
|
||||
|
||||
```
|
||||
|
||||
To validate it, we create a validation object, specify the type of validation, and then check to see if there are any errors:
|
||||
```
|
||||
valid := validation.Validation{}
|
||||
valid.Email(email, "email") // must be a proper email address
|
||||
if valid.HasErrors() {
|
||||
for _, err := range valid.Errors {
|
||||
|
||||
```
|
||||
|
||||
What you do with the errors is up to you. I like to present all of them at once to the user, so as I go through the range of valid.Errors, I add them to a map of errors that will eventually be used in the template file. Hence, the full snippet:
|
||||
```
|
||||
if this.Ctx.Input.Method() == "POST" {
|
||||
email := this.GetString("email")
|
||||
password := this.GetString("password")
|
||||
valid := validation.Validation{}
|
||||
valid.Email(email, "email")
|
||||
valid.Required(password, "password")
|
||||
if valid.HasErrors() {
|
||||
errormap := []string{}
|
||||
for _, err := range valid.Errors {
|
||||
errormap = append(errormap, "Validation failed on "+err.Key+": "+err.Message+"\n")
|
||||
}
|
||||
this.Data["Errors"] = errormap
|
||||
return
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
### The User Management Methods
|
||||
|
||||
We’ve looked at the major pieces of the controller. Now, we get to the meat of the application, the user management methods:
|
||||
|
||||
* Login()
|
||||
* Logout()
|
||||
* Register()
|
||||
* Verify()
|
||||
* Profile()
|
||||
* Remove()
|
||||
|
||||
|
||||
|
||||
Recall that we saw references to these functions in the router. The router associates each URL (and HTTP request) with the corresponding controller method.
|
||||
|
||||
#### Login()
|
||||
|
||||
Let’s look at the pseudocode for this method:
|
||||
```
|
||||
if the HTTP request is "POST" then
|
||||
Validate the form (extract the email address and password).
|
||||
Read the password hash from the database, keying on email.
|
||||
Compare the submitted password with the one on record.
|
||||
Create a session for this user.
|
||||
endif
|
||||
|
||||
```
|
||||
|
||||
In order to compare passwords, we need to give pk.MatchPassword() a variable with members ‘Hash’ and ‘Salt’ that are **byte slices**. Hence,
|
||||
```
|
||||
var x pk.PasswordHash
|
||||
|
||||
```
|
||||
```
|
||||
x.Hash = make([]byte, 32)
|
||||
x.Salt = make([]byte, 16)
|
||||
// after x has the password from the database, then...
|
||||
|
||||
```
|
||||
```
|
||||
if !pk.MatchPassword(password, &x) {
|
||||
flash.Error("Bad password")
|
||||
flash.Store(&this.Controller)
|
||||
return
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
Creating a session is trivial, but we want to store some useful information in the session, as well. So we make a map and store first name, email address, and the time of login:
|
||||
```
|
||||
m := make(map[string]interface{})
|
||||
m["first"] = user.First
|
||||
m["username"] = email
|
||||
m["timestamp"] = time.Now()
|
||||
this.SetSession("acme", m)
|
||||
this.Redirect("/"+back, 302) // go to previous page after login
|
||||
|
||||
```
|
||||
|
||||
Incidentally, the name “acme” passed to SetSession is completely arbitrary; you just need to reference the same name to get the same session.
|
||||
|
||||
#### Logout()
|
||||
|
||||
This one is trivially easy. We delete the session and redirect to the home page.
|
||||
|
||||
#### Register()
|
||||
```
|
||||
if the HTTP request is "POST" then
|
||||
Validate the form.
|
||||
Create the password hash for the submitted password.
|
||||
Prepare new user record.
|
||||
Convert the password hash to hexadecimal string.
|
||||
Generate a UUID and insert the user into database.
|
||||
Send a verification email.
|
||||
Flash a message on the notification page.
|
||||
endif
|
||||
|
||||
```
|
||||
|
||||
To send a verification email to the user, we use **gomail** …
|
||||
```
|
||||
link := "http://localhost:8080/user/verify/" + u // u is UUID
|
||||
host := "smtp.gmail.com"
|
||||
port := 587
|
||||
msg := gomail.NewMessage()
|
||||
msg.SetAddressHeader("From", "acmecorp@gmail.com", "ACME Corporation")
|
||||
msg.SetHeader("To", email)
|
||||
msg.SetHeader("Subject", "Account Verification for ACME Corporation")
|
||||
msg.SetBody("text/html", "To verify your account, please click on the link: <a href=\""+link+"\">"+link+"</a><br><br>Best Regards,<br>ACME Corporation")
|
||||
m := gomail.NewMailer(host, "youraccount@gmail.com", "YourPassword", port)
|
||||
if err := m.Send(msg); err != nil {
|
||||
return false
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
I chose Gmail as my email relay (you will need to open your own account). Note that Gmail ignores the “From” address (in our case, “[acmecorp@gmail.com][18]”) because Gmail does not permit you to alter the sender address in order to prevent phishing.
|
||||
|
||||
#### Notice()
|
||||
|
||||
This special router method is for displaying a flash message on a notification page. It’s not really a user module function; it’s general enough that you can use it in many other places.
|
||||
|
||||
#### Profile()
|
||||
|
||||
We’ve already discussed all the pieces in this function. The pseudocode is:
|
||||
```
|
||||
Login required; check for a session.
|
||||
Get user record from database, keyed on email (or username).
|
||||
if the HTTP request is "POST" then
|
||||
Validate the form.
|
||||
if there is a new password then
|
||||
Validate the new password.
|
||||
Create the password hash for the new password.
|
||||
Convert the password hash to hexadecimal string.
|
||||
endif
|
||||
Compare submitted current password with the one on record.
|
||||
Update the user record.
|
||||
- update the username stored in session
|
||||
endif
|
||||
|
||||
```
|
||||
|
||||
#### Verify()
|
||||
|
||||
The verification email contains a link which, when clicked by the recipient, causes Verify() to process the UUID. Verify() attempts to read the user record, keyed on the UUID or registration key, and if it’s found, then the registration key is removed from the database.
|
||||
|
||||
#### Remove()
|
||||
|
||||
Remove() is pretty much like Login(), except that instead of creating a session, you delete the user record from the database.
|
||||
|
||||
### Exercise
|
||||
|
||||
I left out one user management method: What if the user has forgotten his password? We should provide a way to reset the password. I leave this as an exercise for you. All the pieces you need are in this tutorial. (Hint: You’ll need to do it in a way similar to Registration verification. You should add a new Reset_key to the AuthUser table. And make sure the user email address exists in the database before you send the Reset email!)
|
||||
|
||||
[Okay, so I’ll give you the [exercise solution][19]. I’m not cruel.]
|
||||
|
||||
### Wrapping Up
|
||||
|
||||
Let’s review what we’ve learned. We covered the mapping of URLs to request handlers in the router. We showed how to incorporate a CSS template design into our views. We discussed the ORM package, and how it’s used to perform database operations. We examined a number of third-party utilities useful in writing our application. The end result is a component useful in many scenarios.
|
||||
|
||||
This is a great deal of material in a tutorial, but I believe it’s the best way to get started in writing a practical application.
|
||||
|
||||
[For further material, look at the [sequel][20] to this article, as well as the [final edition][21].]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://medium.com/@richardeng/a-word-from-the-beegoist-d562ff8589d7
|
||||
|
||||
作者：[Richard Kenneth Eng][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://medium.com/@richardeng?source=post_header_lockup
|
||||
[1]:http://tour.golang.org/
|
||||
[2]:http://golang.org/
|
||||
[3]:http://beego.me/
|
||||
[4]:https://medium.com/@richardeng/in-the-beginning-61c7e63a3ea6
|
||||
[5]:http://www.mysql.com/
|
||||
[6]:http://www.sqlite.org/
|
||||
[7]:https://code.google.com/p/liteide/
|
||||
[8]:http://macromates.com/
|
||||
[9]:http://notepad-plus-plus.org/
|
||||
[10]:https://medium.com/@richardeng/back-to-the-future-9db24d6bcee1
|
||||
[11]:http://en.wikipedia.org/wiki/Acme_Corporation
|
||||
[12]:https://github.com/horrido/acme
|
||||
[13]:http://en.wikipedia.org/wiki/Regular_expression
|
||||
[14]:http://en.wikipedia.org/wiki/PBKDF2
|
||||
[15]:http://en.wikipedia.org/wiki/Universally_unique_identifier
|
||||
[16]:http://www.freewebtemplates.com/download/free-website-template/stardust-141989295/
|
||||
[17]:https://cdn-images-1.medium.com/max/1600/1*1OpYy1ISYGUaBy0U_RJ75w.png
|
||||
[18]:mailto:acmecorp@gmail.com
|
||||
[19]:https://github.com/horrido/acme-exercise
|
||||
[20]:https://medium.com/@richardeng/a-word-from-the-beegoist-ii-9561351698eb
|
||||
[21]:https://medium.com/@richardeng/a-word-from-the-beegoist-iii-dbd6308b2594
|
||||
[22]: http://golang.org/
|
||||
[23]: http://beego.me/
|
||||
[24]: http://revel.github.io/
|
||||
[25]: http://www.web2py.com/
|
||||
[26]: https://medium.com/@richardeng/the-zen-of-web2py-ede59769d084
|
||||
[27]: http://www.seaside.st/
|
||||
[28]: http://en.wikipedia.org/wiki/Object-relational_mapping
|
||||
@ -1,285 +0,0 @@
|
||||
pinewall is translating
|
||||
|
||||
Anatomy of a Linux DNS Lookup – Part I
|
||||
============================================================
|
||||
|
||||
Since I [work][3] [a][4] [lot][5] [with][6] [clustered][7] [VMs][8], I’ve ended up spending a lot of time trying to figure out how [DNS lookups][9] work. I applied ‘fixes’ to my problems from StackOverflow without really understanding why they work (or don’t work) for some time.
|
||||
|
||||
Eventually I got fed up with this and decided to figure out how it all hangs together. I couldn’t find a complete guide for this anywhere online, and talking to colleagues they didn’t know of any (or really what happens in detail)
|
||||
|
||||
So I’m writing the guide myself.
|
||||
|
||||
_If you’re looking for Part II, click [here][1]_
|
||||
|
||||
Turns out there’s quite a bit in the phrase ‘Linux does a DNS lookup’…
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_“How hard can it be?”_
|
||||
|
||||
* * *
|
||||
|
||||
These posts are intended to break down how a program decides how it gets an IP address on a Linux host, and the components that can get involved. Without understanding how these pieces fit together, debugging and fixing problems with (for example) `dnsmasq`, `vagrant landrush`, or `resolvconf` can be utterly bewildering.
|
||||
|
||||
It’s also a valuable illustration of how something so simple can get so very complex over time. I’ve looked at over a dozen different technologies and their archaeologies so far while trying to grok what’s going on.
|
||||
|
||||
I even wrote some [automation code][10] to allow me to experiment in a VM. Contributions/corrections are welcome.
|
||||
|
||||
Note that this is not a post on ‘how DNS works’. This is about everything up to the call to the actual DNS server that’s configured on a linux host (assuming it even calls a DNS server – as you’ll see, it need not), and how it might find out which one to go to, or how it gets the IP some other way.
|
||||
|
||||
* * *
|
||||
|
||||
### 1) There is no such thing as a ‘DNS Lookup’ call
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_This is NOT how it works_
|
||||
|
||||
* * *
|
||||
|
||||
The first thing to grasp is that there is no single method of getting a DNS lookup done on Linux. It’s not a core system call with a clean interface.
|
||||
|
||||
There is, however, a standard C library call called which many programs use: `[getaddrinfo][2]`. But not all applications use this!
|
||||
|
||||
Let’s just take two simple standard programs: `ping` and `host`:
|
||||
|
||||
```
|
||||
root@linuxdns1:~# ping -c1 bbc.co.uk | head -1
|
||||
PING bbc.co.uk (151.101.192.81) 56(84) bytes of data.
|
||||
```
|
||||
|
||||
```
|
||||
root@linuxdns1:~# host bbc.co.uk | head -1
|
||||
bbc.co.uk has address 151.101.192.81
|
||||
```
|
||||
|
||||
They both get the same result, so they must be doing the same thing, right?
|
||||
|
||||
Wrong.
|
||||
|
||||
Here’s the files that `ping` looks at on my host that are relevant to DNS:
|
||||
|
||||
```
|
||||
root@linuxdns1:~# strace -e trace=open -f ping -c1 google.com
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/lib/x86_64-linux-gnu/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libnss_files.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/host.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libnss_dns.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libresolv.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
PING google.com (216.58.204.46) 56(84) bytes of data.
|
||||
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 4
|
||||
64 bytes from lhr25s12-in-f14.1e100.net (216.58.204.46): icmp_seq=1 ttl=63 time=13.0 ms
|
||||
[...]
|
||||
```
|
||||
|
||||
and the same for `host`:
|
||||
|
||||
```
|
||||
$ strace -e trace=open -f host google.com
|
||||
[...]
|
||||
[pid 9869] open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/share/locale/en/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/share/locale/en/LC_MESSAGES/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/lib/ssl/openssl.cnf", O_RDONLY) = 6
|
||||
[pid 9869] open("/usr/lib/x86_64-linux-gnu/openssl-1.0.0/engines/libgost.so", O_RDONLY|O_CLOEXEC) = 6[pid 9869] open("/etc/resolv.conf", O_RDONLY) = 6
|
||||
google.com has address 216.58.204.46
|
||||
[...]
|
||||
```
|
||||
|
||||
You can see that while my `ping` looks at `nsswitch.conf`, `host` does not. And they both look at `/etc/resolv.conf`.
|
||||
|
||||
We’re going to take these two `.conf` files in turn.
|
||||
|
||||
* * *
|
||||
|
||||
### 2) NSSwitch, and `/etc/nsswitch.conf`
|
||||
|
||||
We’ve established that applications can do what they like when they decide which DNS server to go to. Many apps (like `ping`) above can refer (depending on the implementation (*)) to NSSwitch via its config file `/etc/nsswitch.conf`.
|
||||
|
||||
###### (*) There’s a surprising degree of variation in
|
||||
ping implementations. That’s a rabbit-hole I
|
||||
_didn’t_ want to get lost in.
|
||||
|
||||
NSSwitch is not just for DNS lookups. It’s also used for passwords and user lookup information (for example).
|
||||
|
||||
NSSwitch was originally created as part of the Solaris OS to allow applications to not have to hard-code which file or service they look these things up on, but defer them to this other configurable centralised place they didn’t have to worry about.
|
||||
|
||||
Here’s my `nsswitch.conf`:
|
||||
|
||||
```
|
||||
passwd: compat
|
||||
group: compat
|
||||
shadow: compat
|
||||
gshadow: files
|
||||
hosts: files dns myhostname
|
||||
networks: files
|
||||
protocols: db files
|
||||
services: db files
|
||||
ethers: db files
|
||||
rpc: db files
|
||||
netgroup: nis
|
||||
```
|
||||
|
||||
The ‘hosts’ line is the one we’re interested in. We’ve shown that `ping` cares about `nsswitch.conf` so let’s fiddle with it and see how we can mess with `ping`.
|
||||
|
||||
* ### Set `nsswitch.conf` to only look at ‘files’
|
||||
|
||||
If you set the `hosts` line in `nsswitch.conf` to be ‘just’ `files`:
|
||||
|
||||
`hosts: files`
|
||||
|
||||
Then a `ping` to google.com will now fail:
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
ping: unknown host google.com
|
||||
```
|
||||
|
||||
but `localhost` still works:
|
||||
|
||||
```
|
||||
$ ping -c1 localhost
|
||||
PING localhost (127.0.0.1) 56(84) bytes of data.
|
||||
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.039 ms
|
||||
```
|
||||
|
||||
and using `host` still works fine:
|
||||
|
||||
```
|
||||
$ host google.com
|
||||
google.com has address 216.58.206.110
|
||||
```
|
||||
|
||||
since, as we saw, it doesn’t care about `nsswitch.conf`
|
||||
|
||||
* ### Set `nsswitch.conf` to only look at ‘dns’
|
||||
|
||||
If you set the `hosts` line in `nsswitch.conf` to be ‘just’ dns:
|
||||
|
||||
`hosts: dns`
|
||||
|
||||
Then a `ping` to google.com will now succeed again:
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
PING google.com (216.58.198.174) 56(84) bytes of data.
|
||||
64 bytes from lhr25s10-in-f174.1e100.net (216.58.198.174): icmp_seq=1 ttl=63 time=8.01 ms
|
||||
```
|
||||
|
||||
But `localhost` is not found this time:
|
||||
|
||||
```
|
||||
$ ping -c1 localhost
|
||||
ping: unknown host localhost
|
||||
```
|
||||
|
||||
Here’s a diagram of what’s going on with NSSwitch by default wrt `hosts` lookup:
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_My default ‘`hosts:`‘ configuration in `nsswitch.conf`_
|
||||
|
||||
* * *
|
||||
|
||||
### 3) `/etc/resolv.conf`
|
||||
|
||||
We’ve seen now that `host` and `ping` both look at this `/etc/resolv.conf` file.
|
||||
|
||||
Here’s what my `/etc/resolv.conf` looks like:
|
||||
|
||||
```
|
||||
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
|
||||
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
|
||||
nameserver 10.0.2.3
|
||||
```
|
||||
|
||||
Ignore the first two lines – we’ll come back to those (they are significant, but you’re not ready for that ball of wool yet).
|
||||
|
||||
The `nameserver` lines specify the DNS servers to look up the host for.
|
||||
|
||||
If you hash out that line:
|
||||
|
||||
```
|
||||
#nameserver 10.0.2.3
|
||||
```
|
||||
|
||||
and run:
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
ping: unknown host google.com
|
||||
```
|
||||
|
||||
it fails, because there’s no nameserver to go to (*).
|
||||
|
||||
###### * Another rabbit hole: `host` appears to fall back to
|
||||
127.0.0.1:53 if there’s no nameserver specified.
|
||||
|
||||
This file takes other options too. For example, if you add this line to the `resolv.conf` file:
|
||||
|
||||
```
|
||||
search com
|
||||
```
|
||||
|
||||
and then `ping google` (sic)
|
||||
|
||||
```
|
||||
$ ping google
|
||||
PING google.com (216.58.204.14) 56(84) bytes of data.
|
||||
```
|
||||
|
||||
it will try the `.com` domain automatically for you.
|
||||
|
||||
### End of Part I
|
||||
|
||||
That’s the end of Part I. The next part will start by looking at how that resolv.conf gets created and updated.
|
||||
|
||||
Here’s what you covered above:
|
||||
|
||||
* There’s no ‘DNS lookup’ call in the OS
|
||||
|
||||
* Different programs figure out the IP of an address in different ways
|
||||
* For example, `ping` uses `nsswitch`, which in turn uses (or can use) `/etc/hosts`, `/etc/resolv.conf` and its own hostname to get the result
|
||||
|
||||
* `/etc/resolv.conf` helps decide:
|
||||
* which addresses get called
|
||||
|
||||
* which DNS server to look up
|
||||
|
||||
If you thought that was complicated, buckle up…
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://zwischenzugs.com/2018/06/08/anatomy-of-a-linux-dns-lookup-part-i/
|
||||
|
||||
作者：[dmatech][a]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://twitter.com/dmatech2
|
||||
[1]:https://zwischenzugs.com/2018/06/18/anatomy-of-a-linux-dns-lookup-part-ii/
|
||||
[2]:http://man7.org/linux/man-pages/man3/getaddrinfo.3.html
|
||||
[3]:https://zwischenzugs.com/2017/10/31/a-complete-chef-infrastructure-on-your-laptop/
|
||||
[4]:https://zwischenzugs.com/2017/03/04/a-complete-openshift-cluster-on-vagrant-step-by-step/
|
||||
[5]:https://zwischenzugs.com/2017/03/04/migrating-an-openshift-etcd-cluster/
|
||||
[6]:https://zwischenzugs.com/2017/03/04/1-minute-multi-node-vm-setup/
|
||||
[7]:https://zwischenzugs.com/2017/03/18/clustered-vm-testing-how-to/
|
||||
[8]:https://zwischenzugs.com/2017/10/27/ten-things-i-wish-id-known-before-using-vagrant/
|
||||
[9]:https://zwischenzugs.com/2017/10/21/openshift-3-6-dns-in-pictures/
|
||||
[10]:https://github.com/ianmiell/shutit-linux-dns/blob/master/linux_dns.py
|
||||
@ -0,0 +1,90 @@
|
||||
How to Install 2048 Game in Ubuntu and Other Linux Distributions
|
||||
======
|
||||
**Popular mobile puzzle game 2048 can also be played on Ubuntu and Linux distributions. Heck! You can even play 2048 in Linux terminal. Don’t blame me if your productivity goes down because of this addictive game.**
|
||||
|
||||
Back in 2014, 2048 was one of the most popular games on iOS and Android. This highly addictive game got so popular that it got a [browser version][1], desktop version as well as a terminal version on Linux.
|
||||
|
||||
<https://giphy.com/embed/wT8XEi5gckwJW>
|
||||
|
||||
This tiny game is played by moving the tiles up and down, left and right. The aim of this puzzle game is to reach 2048 by combining tiles with matching number. So 2+2 becomes 4, 4+4 becomes 16 and so on. It may sound simple and boring but trust me its hell of an addictive game.
|
||||
|
||||
### Play 2048 in Linux [GUI]
|
||||
|
||||
There are several implementations of 2048 game available in Ubuntu and other Linux. You can simply search for it in the Software Center and you’ll find a few of them there.
|
||||
|
||||
There is a [Qt-based][2] 2048 game that you can install on Ubuntu and other Debian and Ubuntu-based Linux distributions. You can install it using the command below:
|
||||
```
|
||||
sudo apt install 2048-qt
|
||||
|
||||
```
|
||||
|
||||
Once installed, you can find the game in the menu and start it. You can move the numbers using the arrow keys. Your highest score is saved as well.
|
||||
|
||||
![2048 Game in Ubuntu Linux][3]
|
||||
|
||||
### Play 2048 in Linux terminal
|
||||
|
||||
The popularity of 2048 brought it to the terminal. If this surprises you, you should know that there are plenty of [awesome terminal games in Linux][4] and 2048 is certainly one of them.
|
||||
|
||||
Now, there are a few ways you can play 2048 in Linux terminal. I’ll mention two of them here.
|
||||
|
||||
#### 1\. term2058 Snap application
|
||||
|
||||
There is a [snap application][5] called [term2048][6] that you can install in any [Snap supported Linux distribution][7].
|
||||
|
||||
If you have Snap enabled, just use this command to install term2048:
|
||||
```
|
||||
sudo snap install term2048
|
||||
|
||||
```
|
||||
|
||||
Ubuntu users can also find this game in the Software Center and install it from there.
|
||||
|
||||
![2048 Terminal Game in Linux][8]
|
||||
|
||||
Once installed, you can use the command term2048 to run the game. It looks something like this:
|
||||
|
||||
![2048 Terminal game][9]
|
||||
|
||||
You can move using the arrow keys.
|
||||
|
||||
#### 2\. Bash script for 2048 terminal game
|
||||
|
||||
This game is actually a shell script which you can run in any Linux terminal. Download the game/script from Github:
|
||||
|
||||
[Download Bash2048][10]
|
||||
|
||||
Extract the downloaded file. Go in the extracted directory and you’ll see a shell script named 2048.sh. Just run the shell script. The game will start immediately. You can move the tiles using the arrow keys.
|
||||
|
||||
![Linux Terminal game 2048][11]
|
||||
|
||||
#### What games do you play on Linux?
|
||||
|
||||
If you like playing games in Linux terminal, you should also try the [classic Snake game in Linux terminal][12].
|
||||
|
||||
Which games do you regularly play in Linux? Do you also play games in terminal? If yes, which is your favorite terminal game?
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/2048-game/
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/abhishek/
|
||||
[1]:http://gabrielecirulli.github.io/2048/
|
||||
[2]:https://www.qt.io/
|
||||
[3]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/2048-qt-ubuntu.jpeg
|
||||
[4]:https://itsfoss.com/best-command-line-games-linux/
|
||||
[5]:https://itsfoss.com/use-snap-packages-ubuntu-16-04/
|
||||
[6]:https://snapcraft.io/term2048
|
||||
[7]:https://itsfoss.com/install-snap-linux/
|
||||
[8]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/term2048-game.png
|
||||
[9]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/term2048.jpg
|
||||
[10]:https://github.com/mydzor/bash2048
|
||||
[11]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/2048-bash-terminal.png
|
||||
[12]:https://itsfoss.com/nsnake-play-classic-snake-game-linux-terminal/ (nSnake: Play The Classic Snake Game In Linux Terminal)
|
||||
@ -0,0 +1,237 @@
|
||||
System Snapshot And Restore Utility For Linux
|
||||
======
|
||||
|
||||
|
||||
**CYA** , stands for **C** over **Y** our **A** ssets, is a free, open source system snapshot and restore utility for any Unix-like operating systems that uses BASH shell. Cya is portable and supports many popular filesystems such as EXT2/3/4, XFS, UFS, GPFS, reiserFS, JFS, BtrFS, and ZFS etc. Please note that **Cya will not backup the actual user data**. It only backups and restores the operating system itself and not your actual user data. **Cya is a system restore utility**. By default, it will backup all key directories like /bin/, /lib/, /usr/, /var/ and several others. You can, however, define your own directories and files path to include in the backup, so Cya will pick those up as well. Also, it is possible define some directories/files to skip from the backup. For example, you can skip /var/logs/ if you don’t log files. Cya actually uses **Rsync** backup method under the hood. However, Cya is super easier than Rsync when creating rolling backups.
|
||||
|
||||
When restoring your operating system, Cya will rollback the OS using your backup profile which you created earlier. You can either restore the entire system or any specific directories only. Also, you can easily access the backup files even without a complete rollback using your terminal or file manager. ANother notable feature is we can generate a custom recovery script to automate the mounting of your system partition(s) when you restore off a live CD, USB, or network image. In a nutshell, CYA can help you to restore your system to previous states when you end-up with a broken system caused by software update, configuration changes, intrusions/hacks, etc.
|
||||
|
||||
### Installing CYA
|
||||
|
||||
Installing CYA is very easy. All you have to do is download Cya binary and put it in your system path.
|
||||
```
|
||||
$ git clone https://github.com/cleverwise/cya.git
|
||||
|
||||
```
|
||||
|
||||
This will clone the latest cya version in a directory called cya in your current working directory.
|
||||
|
||||
Next, copy the cya binary to your path or wherever you want.
|
||||
```
|
||||
$ sudo cp cya/cya /usr/local/bin/
|
||||
|
||||
```
|
||||
|
||||
CYA as been installed. Now let us go ahead and create snapshots.
|
||||
|
||||
### Creating Snapshots
|
||||
|
||||
Before creating any snapshots/backups, create a recovery script using command:
|
||||
```
|
||||
$ cya script
|
||||
☀ Cover Your Ass(ets) v2.2 ☀
|
||||
|
||||
ACTION ⯮ Generating Recovery Script
|
||||
|
||||
Generating Linux recovery script ...
|
||||
Checking sudo permissions...
|
||||
Complete
|
||||
|
||||
IMPORTANT: This script will ONLY mount / and /home. Thus if you are storing data on another mount point open the recovery.sh script and add the additional mount point command where necessary. This is also a best guess and should be tested before an emergency to verify it works as desired.
|
||||
|
||||
|
||||
‣ Disclaimer: CYA offers zero guarantees as improper usage can cause undesired results
|
||||
‣ Notice: Proper usage can correct unauthorized changes to system from attacks
|
||||
|
||||
```
|
||||
|
||||
Save the resulting **recovery.sh** file in your USB drive which we are going to use it later when restoring backups. This script will help you to setup a chrooted environment and mount drives when you rollback your system.
|
||||
|
||||
Now, let us create snapshots.
|
||||
|
||||
To create a standard rolling backup, run:
|
||||
```
|
||||
$ cya save
|
||||
|
||||
```
|
||||
|
||||
The above command will keep **three backups** before overwriting.
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
☀ Cover Your Ass(ets) v2.2 ☀
|
||||
|
||||
ACTION ⯮ Standard Backup
|
||||
|
||||
Checking sudo permissions...
|
||||
[sudo] password for sk:
|
||||
We need to create /home/cya/points/1 ... done
|
||||
Backing up /bin/ ... complete
|
||||
Backing up /boot/ ... complete
|
||||
Backing up /etc/ ... complete
|
||||
.
|
||||
.
|
||||
.
|
||||
Backing up /lib/ ... complete
|
||||
Backing up /lib64/ ... complete
|
||||
Backing up /opt/ ... complete
|
||||
Backing up /root/ ... complete
|
||||
Backing up /sbin/ ... complete
|
||||
Backing up /snap/ ... complete
|
||||
Backing up /usr/ ... complete
|
||||
Backing up /initrd.img ... complete
|
||||
Backing up /initrd.img.old ... complete
|
||||
Backing up /vmlinuz ... complete
|
||||
Backing up /vmlinuz.old ... complete
|
||||
Write out date file ... complete
|
||||
Update rotation file ... complete
|
||||
|
||||
‣ Disclaimer: CYA offers zero guarantees as improper usage can cause undesired results
|
||||
‣ Notice: Proper usage can correct unauthorized changes to system from attacks
|
||||
|
||||
```
|
||||
|
||||
You can view the contents of the newly created snapshot, under **/home/cya/points/** location.
|
||||
```
|
||||
$ ls /home/cya/points/1/
|
||||
bin cya-date initrd.img lib opt sbin usr vmlinuz
|
||||
boot etc initrd.img.old lib64 root snap var vmlinuz.old
|
||||
|
||||
```
|
||||
|
||||
To create a backup with a custom name that will not be overwritten, run:
|
||||
```
|
||||
$ cya keep name BACKUP_NAME
|
||||
|
||||
```
|
||||
|
||||
Replace **BACKUP_NAME** with your own name.
|
||||
|
||||
To create a backup with a custom name that will overwrite, do:
|
||||
```
|
||||
$ cya keep name BACKUP_NAME overwrite
|
||||
|
||||
```
|
||||
|
||||
To create a backup and archive and compress it, run:
|
||||
```
|
||||
$ cya keep name BACKUP_NAME archive
|
||||
|
||||
```
|
||||
|
||||
This command will store the backups in **/home/cya/archives** location.
|
||||
|
||||
By default, CYA will store its configuration in **/home/cya/** directory and the snapshots with a custom name will be stored in **/home/cya/points/BACKUP_NAME** location. You can, however, change these settings by editing the CYA configuration file stored at **/home/cya/cya.conf**.
|
||||
|
||||
Like I already said, CYA will not backup user data by default. It will only backup the important system files. You can, however, include your own directories or files along with system files. Say for example, if you wanted to add the directory named **/home/sk/Downloads** directory in the backup, edit **/home/cya/cya.conf** file:
|
||||
```
|
||||
$ vi /home/cya/cya.conf
|
||||
|
||||
```
|
||||
|
||||
Define your directory data path that you wanted to include in the backup like below.
|
||||
```
|
||||
MYDATA_mybackup="/home/sk/Downloads/ /mnt/backup/sk/"
|
||||
|
||||
```
|
||||
|
||||
Please be mindful that both source and destination directories should end with a trailing slash. As per the above configuration, CYA will copy all the contents of **/home/sk/Downloads/** directory and save them in **/mnt/backup/sk/** (assuming you already created this) directory. Here **mybackup** is the profile name. Save and close the file.
|
||||
|
||||
Now to backup the contents of /home/sk/Downloads/ directory, you need to enter the profile name (i.e mybackup in my case) with the **cya mydata** command like below:
|
||||
```
|
||||
$ cya mydata mybackup
|
||||
|
||||
```
|
||||
|
||||
Similarly, you can include multiple user data with a different profile names. All profile names must be unique.
|
||||
|
||||
### Exclude directories
|
||||
|
||||
Some times, you may not want to backup all system files. You might want to exclude some unimportant such as log files. For example, if you don’t want to include **/var/tmp/** and **/var/logs/** directories, add the following in **/home/cya/cya.conf** file.
|
||||
```
|
||||
EXCLUDE_/var/=”tmp/ logs/”
|
||||
|
||||
```
|
||||
|
||||
Similarly, you can specify all directories one by one that you want to exclude from the backup. Once done, save and close the file.
|
||||
|
||||
### Add specific files to the backup
|
||||
|
||||
Instead of backing up whole directories, you can include a specific files from a directory. To do so, add the path of your files one by one in **/home/cya/cya.conf** file.
|
||||
```
|
||||
BACKUP_FILES="/home/sk/Downloads/ostechnix.txt"
|
||||
|
||||
```
|
||||
|
||||
### Restore your system
|
||||
|
||||
Remember, we already create a recovery script named **recovery.sh** and saved it in an USB drive? Yeah, we will need it now to restore our broken system.
|
||||
|
||||
Boot your system with any live bootable CD/DVD, USB drive. The developer of CYA recommends to use a live boot environment from same major version as your installed environment! For example if you use Ubuntu 18.04 system, then use Ubuntu 18.04 live media.
|
||||
|
||||
Once you’re in the live system, mount the USB drive that contains the recovery.sh script. Once you mounted the drive(s), your system’s **/** and **/home** will be mounted to the **/mnt/cya** directory. This is made really easy and handled automatically by the **recovery.sh** script for Linux users.
|
||||
|
||||
Then, start the restore process using command:
|
||||
```
|
||||
$ sudo /mnt/cya/home/cya/cya restore
|
||||
|
||||
```
|
||||
|
||||
Just follow the onscreen instructions. Once the restoration is done, remove the live media and unmount the drives and finally, reboot your system.
|
||||
|
||||
What if you don’t have or lost recovery script? No problem, we still can restore our broken system.
|
||||
|
||||
Boot the live media. From the live session, create a directory to mount the drive(s).
|
||||
```
|
||||
$ sudo mkdir -p /mnt/cya
|
||||
|
||||
```
|
||||
|
||||
Then, mount your **/** and **/home** (if on another partition) into the **/mnt/cya** directory.
|
||||
```
|
||||
$ sudo mount /dev/sda1 /mnt/cya
|
||||
|
||||
$ sudo mount /dev/sda3 /mnt/cya/home
|
||||
|
||||
```
|
||||
|
||||
Replace /dev/sda1 and /dev/sda3 with your correct partitions (Use **fdisk -l** command to find your partitions).
|
||||
|
||||
Finally, start the restoration process using command:
|
||||
```
|
||||
$ sudo /mnt/cya/home/cya/cya restore
|
||||
|
||||
```
|
||||
|
||||
Once the recovery is completed, unmount all mounted partitions and remove install media and reboot your system.
|
||||
|
||||
At this stage, you might get a working system. I deleted some important libraries in Ubuntu 18.04 LTS server. I successfully restored it to the working state by using CYA utility.
|
||||
|
||||
### Schedule CYA backup
|
||||
|
||||
It is always recommended to use crontab to schedule the CYA snapshot process at regular interval. You can setup a cron job using root or setup a user that doesn’t need to enter a sudo password.
|
||||
|
||||
The example entry below will run cya at every Monday at 2:05 am with output dumped into /dev/null.
|
||||
```
|
||||
5 2 * * 1 /home/USER/bin/cya save >/dev/null 2>&1
|
||||
|
||||
```
|
||||
|
||||
And, that’s all for now. Unlike Systemback and other system restore utilities, Cya is not a distribution-specific restore utility. It supports many Linux operating systems that uses BASH. It is one of the must-have applications in your arsenal. Install it right away and create snapshots. You won’t regret when you accidentally crashed your Linux system.
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/cya-system-snapshot-and-restore-utility-for-linux/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.ostechnix.com/author/sk/
|
||||
@ -0,0 +1,988 @@
|
||||
75 Most Used Essential Linux Applications of 2018
|
||||
======
|
||||
|
||||
**2018** has been an awesome year for a lot of applications, especially those that are both free and open source. And while various Linux distributions come with a number of default apps, users are free to take them out and use any of the free or paid alternatives of their choice.
|
||||
|
||||
Today, we bring you a [list of Linux applications][3] that have been able to make it to users’ Linux installations almost all the time despite the butt-load of other alternatives.
|
||||
|
||||
To simply put, any app on this list is among the most used in its category, and if you haven’t already tried it out you are probably missing out. Enjoy!
|
||||
|
||||
### Backup Tools
|
||||
|
||||
#### Rsync
|
||||
|
||||
[Rsync][4] is an open source bandwidth-friendly utility tool for performing swift incremental file transfers and it is available for free.
|
||||
```
|
||||
$ rsync [OPTION...] SRC... [DEST]
|
||||
|
||||
```
|
||||
|
||||
To know more examples and usage, read our article “[10 Practical Examples of Rsync Command][5]” to learn more about it.
|
||||
|
||||
#### Timeshift
|
||||
|
||||
[Timeshift][6] provides users with the ability to protect their system by taking incremental snapshots which can be reverted to at a different date – similar to the function of Time Machine in Mac OS and System restore in Windows.
|
||||
|
||||
|
||||
|
||||
### BitTorrent Client
|
||||
|
||||
|
||||
|
||||
#### Deluge
|
||||
|
||||
[Deluge][7] is a beautiful cross-platform BitTorrent client that aims to perfect the **μTorrent** experience and make it available to users for free.
|
||||
|
||||
Install **Deluge** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:deluge-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install deluge
|
||||
|
||||
```
|
||||
|
||||
#### qBittorent
|
||||
|
||||
[qBittorent][8] is an open source BitTorrent protocol client that aims to provide a free alternative to torrent apps like μTorrent.
|
||||
|
||||
Install **qBittorent** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:qbittorrent-team/qbittorrent-stable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install qbittorrent
|
||||
|
||||
```
|
||||
|
||||
#### Transmission
|
||||
|
||||
[Transmission][9] is also a BitTorrent client with awesome functionalities and a major focus on speed and ease of use. It comes preinstalled with many Linux distros.
|
||||
|
||||
Install **Transmission** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:transmissionbt/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install transmission-gtk transmission-cli transmission-common transmission-daemon
|
||||
|
||||
```
|
||||
|
||||
### Cloud Storage
|
||||
|
||||
|
||||
|
||||
#### Dropbox
|
||||
|
||||
The [Dropbox][10] team rebranded their cloud service earlier this year to provide an even better performance and app integration for their clients. It starts with 2GB of storage for free.
|
||||
|
||||
Install **Dropbox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86" | tar xzf - [On 32-Bit]
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf - [On 64-Bit]
|
||||
$ ~/.dropbox-dist/dropboxd
|
||||
|
||||
```
|
||||
|
||||
#### Google Drive
|
||||
|
||||
[Google Drive][11] is Google’s cloud service solution and my guess is that it needs no introduction. Just like with **Dropbox** , you can sync files across all your connected devices. It starts with 15GB of storage for free and this includes Gmail, Google photos, Maps, etc.
|
||||
|
||||
Check out: [5 Google Drive Clients for Linux][12]
|
||||
|
||||
#### Mega
|
||||
|
||||
[Mega][13] stands out from the rest because apart from being extremely security-conscious, it gives free users 50GB to do as they wish! Its end-to-end encryption ensures that they can’t access your data, and if you forget your recovery key, you too wouldn’t be able to.
|
||||
|
||||
[**Download MEGA Cloud Storage for Ubuntu][14]
|
||||
|
||||
### Commandline Editors
|
||||
|
||||
|
||||
|
||||
#### Vim
|
||||
|
||||
[Vim][15] is an open source clone of vi text editor developed to be customizable and able to work with any type of text.
|
||||
|
||||
Install **Vim** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/vim
|
||||
$ sudo apt update
|
||||
$ sudo apt install vim
|
||||
|
||||
```
|
||||
|
||||
#### Emacs
|
||||
|
||||
[Emacs][16] refers to a set of highly configurable text editors. The most popular variant, GNU Emacs, is written in Lisp and C to be self-documenting, extensible, and customizable.
|
||||
|
||||
Install **Emacs** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kelleyk/emacs
|
||||
$ sudo apt update
|
||||
$ sudo apt install emacs25
|
||||
|
||||
```
|
||||
|
||||
#### Nano
|
||||
|
||||
[Nano][17] is a feature-rich CLI text editor for power users and it has the ability to work with different terminals, among other functionalities.
|
||||
|
||||
Install **Nano** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:n-muench/programs-ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install nano
|
||||
|
||||
```
|
||||
|
||||
### Download Manager
|
||||
|
||||
|
||||
|
||||
#### Aria2
|
||||
|
||||
[Aria2][18] is an open source lightweight multi-source and multi-protocol command line-based downloader with support for Metalinks, torrents, HTTP/HTTPS, SFTP, etc.
|
||||
|
||||
Install **Aria2** on **Ubuntu** and **Debian** , using following command.
|
||||
```
|
||||
$ sudo apt-get install aria2
|
||||
|
||||
```
|
||||
|
||||
#### uGet
|
||||
|
||||
[uGet][19] has earned its title as the **#1** open source download manager for Linux distros and it features the ability to handle any downloading task you can throw at it including using multiple connections, using queues, categories, etc.
|
||||
|
||||
Install **uGet** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:plushuang-tw/uget-stable
|
||||
$ sudo apt update
|
||||
$ sudo apt install uget
|
||||
|
||||
```
|
||||
|
||||
#### XDM
|
||||
|
||||
[XDM][20], **Xtreme Download Manager** is an open source downloader written in Java. Like any good download manager, it can work with queues, torrents, browsers, and it also includes a video grabber and a smart scheduler.
|
||||
|
||||
Install **XDM** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:noobslab/apps
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install xdman
|
||||
|
||||
```
|
||||
|
||||
### Email Clients
|
||||
|
||||
|
||||
|
||||
#### Thunderbird
|
||||
|
||||
[Thunderbird][21] is among the most popular email applications. It is free, open source, customizable, feature-rich, and above all, easy to install.
|
||||
|
||||
Install **Thunderbird** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install thunderbird
|
||||
|
||||
```
|
||||
|
||||
#### Geary
|
||||
|
||||
[Geary][22] is an open source email client based on WebKitGTK+. It is free, open-source, feature-rich, and adopted by the GNOME project.
|
||||
|
||||
Install **Geary** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:geary-team/releases
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geary
|
||||
|
||||
```
|
||||
|
||||
#### Evolution
|
||||
|
||||
[Evolution][23] is a free and open source email client for managing emails, meeting schedules, reminders, and contacts.
|
||||
|
||||
Install **Evolution** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnome3-team/gnome3-staging
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install evolution
|
||||
|
||||
```
|
||||
|
||||
### Finance Software
|
||||
|
||||
|
||||
|
||||
#### GnuCash
|
||||
|
||||
[GnuCash][24] is a free, cross-platform, and open source software for financial accounting tasks for personal and small to mid-size businesses.
|
||||
|
||||
Install **GnuCash** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo sh -c 'echo "deb http://archive.getdeb.net/ubuntu $(lsb_release -sc)-getdeb apps" >> /etc/apt/sources.list.d/getdeb.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnucash
|
||||
|
||||
```
|
||||
|
||||
#### KMyMoney
|
||||
|
||||
[KMyMoney][25] is a finance manager software that provides all important features found in the commercially-available, personal finance managers.
|
||||
|
||||
Install **KMyMoney** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:claydoh/kmymoney2-kde4
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kmymoney
|
||||
|
||||
```
|
||||
|
||||
### IDE Editors
|
||||
|
||||
|
||||
|
||||
#### Eclipse IDE
|
||||
|
||||
[Eclipse][26] is the most widely used Java IDE containing a base workspace and an impossible-to-overemphasize configurable plug-in system for personalizing its coding environment.
|
||||
|
||||
For installation, read our article “[How to Install Eclipse Oxygen IDE in Debian and Ubuntu][27]”
|
||||
|
||||
#### Netbeans IDE
|
||||
|
||||
A fan-favourite, [Netbeans][28] enables users to easily build applications for mobile, desktop, and web platforms using Java, PHP, HTML5, JavaScript, and C/C++, among other languages.
|
||||
|
||||
For installation, read our article “[How to Install Netbeans Oxygen IDE in Debian and Ubuntu][29]”
|
||||
|
||||
#### Brackets
|
||||
|
||||
[Brackets][30] is an advanced text editor developed by Adobe to feature visual tools, preprocessor support, and a design-focused user flow for web development. In the hands of an expert, it can serve as an IDE in its own right.
|
||||
|
||||
Install **Brackets** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:webupd8team/brackets
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install brackets
|
||||
|
||||
```
|
||||
|
||||
#### Atom IDE
|
||||
|
||||
[Atom IDE][31] is a more robust version of Atom text editor achieved by adding a number of extensions and libraries to boost its performance and functionalities. It is, in a sense, Atom on steroids.
|
||||
|
||||
Install **Atom** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
|
||||
```
|
||||
|
||||
#### Light Table
|
||||
|
||||
[Light Table][32] is a self-proclaimed next-generation IDE developed to offer awesome features like data value flow stats and coding collaboration.
|
||||
|
||||
Install **Light Table** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dr-akulavich/lighttable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lighttable-installer
|
||||
|
||||
```
|
||||
|
||||
#### Visual Studio Code
|
||||
|
||||
[Visual Studio Code][33] is a source code editor created by Microsoft to offer users the best-advanced features in a text editor including syntax highlighting, code completion, debugging, performance statistics and graphs, etc.
|
||||
|
||||
[**Download Visual Studio Code for Ubuntu][34]
|
||||
|
||||
### Instant Messaging
|
||||
|
||||
|
||||
|
||||
#### Pidgin
|
||||
|
||||
[Pidgin][35] is an open source instant messaging app that supports virtually all chatting platforms and can have its abilities extended using extensions.
|
||||
|
||||
Install **Pidgin** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/backports
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install pidgin
|
||||
|
||||
```
|
||||
|
||||
#### Skype
|
||||
|
||||
[Skype][36] needs no introduction and its awesomeness is available for any interested Linux user.
|
||||
|
||||
Install **Skype** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install snapd
|
||||
$ sudo snap install skype --classic
|
||||
|
||||
```
|
||||
|
||||
#### Empathy
|
||||
|
||||
[Empathy][37] is a messaging app with support for voice, video chat, text, and file transfers over multiple several protocols. It also allows you to add other service accounts to it and interface with all of them through it.
|
||||
|
||||
Install **Empathy** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install empathy
|
||||
|
||||
```
|
||||
|
||||
### Linux Antivirus
|
||||
|
||||
#### ClamAV/ClamTk
|
||||
|
||||
[ClamAV][38] is an open source and cross-platform command line antivirus app for detecting Trojans, viruses, and other malicious codes. [ClamTk][39] is its GUI front-end.
|
||||
|
||||
Install **ClamAV/ClamTk** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install clamav
|
||||
$ sudo apt-get install clamtk
|
||||
|
||||
```
|
||||
|
||||
### Linux Desktop Environments
|
||||
|
||||
#### Cinnamon
|
||||
|
||||
[Cinnamon][40] is a free and open-source derivative of **GNOME3** and it follows the traditional desktop metaphor conventions.
|
||||
|
||||
Install **Cinnamon** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:embrosyn/cinnamon
|
||||
$ sudo apt update
|
||||
$ sudo apt install cinnamon-desktop-environment lightdm
|
||||
|
||||
```
|
||||
|
||||
#### Mate
|
||||
|
||||
The [Mate][41] Desktop Environment is a derivative and continuation of **GNOME2** developed to offer an attractive UI on Linux using traditional metaphors.
|
||||
|
||||
Install **Mate** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-mate-desktop
|
||||
|
||||
```
|
||||
|
||||
#### GNOME
|
||||
|
||||
[GNOME][42] is a Desktop Environment comprised of several free and open-source applications and can run on any Linux distro and on most BSD derivatives.
|
||||
|
||||
Install **Gnome** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-desktop
|
||||
|
||||
```
|
||||
|
||||
#### KDE
|
||||
|
||||
[KDE][43] is developed by the KDE community to provide users with a graphical solution to interfacing with their system and performing several computing tasks.
|
||||
|
||||
Install **KDE** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install kubuntu-desktop
|
||||
|
||||
```
|
||||
|
||||
### Linux Maintenance Tools
|
||||
|
||||
#### GNOME Tweak Tool
|
||||
|
||||
The [GNOME Tweak Tool][44] is the most popular tool for customizing and tweaking GNOME3 and GNOME Shell settings.
|
||||
|
||||
Install **GNOME Tweak Tool** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install gnome-tweak-tool
|
||||
|
||||
```
|
||||
|
||||
#### Stacer
|
||||
|
||||
[Stacer][45] is a free, open-source app for monitoring and optimizing Linux systems.
|
||||
|
||||
Install **Stacer** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:oguzhaninan/stacer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install stacer
|
||||
|
||||
```
|
||||
|
||||
#### BleachBit
|
||||
|
||||
[BleachBit][46] is a free disk space cleaner that also works as a privacy manager and system optimizer.
|
||||
|
||||
[**Download BleachBit for Ubuntu][47]
|
||||
|
||||
### Linux Terminals
|
||||
|
||||
#### GNOME Terminal
|
||||
|
||||
[GNOME Terminal][48] is GNOME’s default terminal emulator.
|
||||
|
||||
Install **Gnome Terminal** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install gnome-terminal
|
||||
|
||||
```
|
||||
|
||||
#### Konsole
|
||||
|
||||
[Konsole][49] is a terminal emulator for KDE.
|
||||
|
||||
Install **Konsole** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install konsole
|
||||
|
||||
```
|
||||
|
||||
#### Terminator
|
||||
|
||||
[Terminator][50] is a feature-rich GNOME Terminal-based terminal app built with a focus on arranging terminals, among other functions.
|
||||
|
||||
Install **Terminator** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install terminator
|
||||
|
||||
```
|
||||
|
||||
#### Guake
|
||||
|
||||
[Guake][51] is a lightweight drop-down terminal for the GNOME Desktop Environment.
|
||||
|
||||
Install **Guake** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install guake
|
||||
|
||||
```
|
||||
|
||||
### Multimedia Editors
|
||||
|
||||
#### Ardour
|
||||
|
||||
[Ardour][52] is a beautiful Digital Audio Workstation (DAW) for recording, editing, and mixing audio professionally.
|
||||
|
||||
Install **Ardour** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dobey/audiotools
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install ardour
|
||||
|
||||
```
|
||||
|
||||
#### Audacity
|
||||
|
||||
[Audacity][53] is an easy-to-use cross-platform and open source multi-track audio editor and recorder; arguably the most famous of them all.
|
||||
|
||||
Install **Audacity** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntuhandbook1/audacity
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install audacity
|
||||
|
||||
```
|
||||
|
||||
#### GIMP
|
||||
|
||||
[GIMP][54] is the most popular open source Photoshop alternative and it is for a reason. It features various customization options, 3rd-party plugins, and a helpful user community.
|
||||
|
||||
Install **Gimp** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:otto-kesselgulasch/gimp
|
||||
$ sudo apt update
|
||||
$ sudo apt install gimp
|
||||
|
||||
```
|
||||
|
||||
#### Krita
|
||||
|
||||
[Krita][55] is an open source painting app that can also serve as an image manipulating tool and it features a beautiful UI with a reliable performance.
|
||||
|
||||
Install **Krita** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kritalime/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install krita
|
||||
|
||||
```
|
||||
|
||||
#### Lightworks
|
||||
|
||||
[Lightworks][56] is a powerful, flexible, and beautiful tool for editing videos professionally. It comes feature-packed with hundreds of amazing effects and presets that allow it to handle any editing task that you throw at it and it has 25 years of experience to back up its claims.
|
||||
|
||||
[**Download Lightworks for Ubuntu][57]
|
||||
|
||||
#### OpenShot
|
||||
|
||||
[OpenShot][58] is an award-winning free and open source video editor known for its excellent performance and powerful capabilities.
|
||||
|
||||
Install **Openshot** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:openshot.developers/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install openshot-qt
|
||||
|
||||
```
|
||||
|
||||
#### PiTiV
|
||||
|
||||
[Pitivi][59] is a beautiful video editor that features a beautiful code base, awesome community, is easy to use, and allows for hassle-free collaboration.
|
||||
|
||||
Install **PiTiV** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ flatpak install --user https://flathub.org/repo/appstream/org.pitivi.Pitivi.flatpakref
|
||||
$ flatpak install --user http://flatpak.pitivi.org/pitivi.flatpakref
|
||||
$ flatpak run org.pitivi.Pitivi//stable
|
||||
|
||||
```
|
||||
|
||||
### Music Players
|
||||
|
||||
#### Rhythmbox
|
||||
|
||||
[Rhythmbox][60] posses the ability to perform all music tasks you throw at it and has so far proved to be a reliable music player that it ships with Ubuntu.
|
||||
|
||||
Install **Rhythmbox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:fossfreedom/rhythmbox
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install rhythmbox
|
||||
|
||||
```
|
||||
|
||||
#### Lollypop
|
||||
|
||||
[Lollypop][61] is a beautiful, relatively new, open source music player featuring a number of advanced options like online radio, scrubbing support and party mode. Yet, it manages to keep everything simple and easy to manage.
|
||||
|
||||
Install **Lollypop** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnumdk/lollypop
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lollypop
|
||||
|
||||
```
|
||||
|
||||
#### Amarok
|
||||
|
||||
[Amarok][62] is a robust music player with an intuitive UI and tons of advanced features bundled into a single unit. It also allows users to discover new music based on their genre preferences.
|
||||
|
||||
Install **Amarok** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install amarok
|
||||
|
||||
```
|
||||
|
||||
#### Clementine
|
||||
|
||||
[Clementine][63] is an Amarok-inspired music player that also features a straight-forward UI, advanced control features, and the ability to let users search for and discover new music.
|
||||
|
||||
Install **Clementine** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:me-davidsansome/clementine
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install clementine
|
||||
|
||||
```
|
||||
|
||||
#### Cmus
|
||||
|
||||
[Cmus][64] is arguably the most efficient CLI music player, Cmus is fast and reliable, and its functionality can be increased using extensions.
|
||||
|
||||
Install **Cmus** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jmuc/cmus
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install cmus
|
||||
|
||||
```
|
||||
|
||||
### Office Suites
|
||||
|
||||
#### Calligra Suite
|
||||
|
||||
The [Calligra Suite][65] provides users with a set of 8 applications which cover working with office, management, and graphics tasks.
|
||||
|
||||
Install **Calligra Suite** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install calligra
|
||||
|
||||
```
|
||||
|
||||
#### LibreOffice
|
||||
|
||||
[LibreOffice][66] the most actively developed office suite in the open source community, LibreOffice is known for its reliability and its functions can be increased using extensions.
|
||||
|
||||
Install **LibreOffice** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:libreoffice/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install libreoffice
|
||||
|
||||
```
|
||||
|
||||
#### WPS Office
|
||||
|
||||
[WPS Office][67] is a beautiful office suite alternative with a more modern UI.
|
||||
|
||||
[**Download WPS Office for Ubuntu][68]
|
||||
|
||||
### Screenshot Tools
|
||||
|
||||
#### Shutter
|
||||
|
||||
[Shutter][69] allows users to take screenshots of their desktop and then edit them using filters and other effects coupled with the option to upload and share them online.
|
||||
|
||||
Install **Shutter** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository -y ppa:shutter/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install shutter
|
||||
|
||||
```
|
||||
|
||||
#### Kazam
|
||||
|
||||
[Kazam][70] screencaster captures screen content to output a video and audio file supported by any video player with VP8/WebM and PulseAudio support.
|
||||
|
||||
Install **Kazam** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kazam-team/unstable-series
|
||||
$ sudo apt update
|
||||
$ sudo apt install kazam python3-cairo python3-xlib
|
||||
|
||||
```
|
||||
|
||||
#### Gnome Screenshot
|
||||
|
||||
[Gnome Screenshot][71] was once bundled with Gnome utilities but is now a standalone app. It can be used to take screencasts in a format that is easily shareable.
|
||||
|
||||
Install **Gnome Screenshot** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnome-screenshot
|
||||
|
||||
```
|
||||
|
||||
### Screen Recorders
|
||||
|
||||
#### SimpleScreenRecorder
|
||||
|
||||
[SimpleScreenRecorder][72] was created to be better than the screen-recording apps available at the time of its creation and has now turned into one of the most efficient and easy-to-use screen recorders for Linux distros.
|
||||
|
||||
Install **SimpleScreenRecorder** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install simplescreenrecorder
|
||||
|
||||
```
|
||||
|
||||
#### recordMyDesktop
|
||||
|
||||
[recordMyDesktop][73] is an open source session recorder that is also capable of recording desktop session audio.
|
||||
|
||||
Install **recordMyDesktop** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gtk-recordmydesktop
|
||||
|
||||
```
|
||||
|
||||
### Text Editors
|
||||
|
||||
#### Atom
|
||||
|
||||
[Atom][74] is a modern and customizable text editor created and maintained by GitHub. It is ready for use right out of the box and can have its functionality enhanced and its UI customized using extensions and themes.
|
||||
|
||||
Install **Atom** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
|
||||
```
|
||||
|
||||
#### Sublime Text
|
||||
|
||||
[Sublime Text][75] is easily among the most awesome text editors to date. It is customizable, lightweight (even when bulldozed with a lot of data files and extensions), flexible, and remains free to use forever.
|
||||
|
||||
Install **Sublime Text** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install sublime-text
|
||||
|
||||
```
|
||||
|
||||
#### Geany
|
||||
|
||||
[Geany][76] is a memory-friendly text editor with basic IDE features designed to exhibit shot load times and extensible functions using libraries.
|
||||
|
||||
Install **Geany** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geany
|
||||
|
||||
```
|
||||
|
||||
#### Gedit
|
||||
|
||||
[Gedit][77] is famous for its simplicity and it comes preinstalled with many Linux distros because of its function as an excellent general purpose text editor.
|
||||
|
||||
Install **Gedit** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gedit
|
||||
|
||||
```
|
||||
|
||||
### To-Do List Apps
|
||||
|
||||
#### Evernote
|
||||
|
||||
[Evernote][78] is a cloud-based note-taking productivity app designed to work perfectly with different types of notes including to-do lists and reminders.
|
||||
|
||||
There is no any official evernote app for Linux, so check out other third party [6 Evernote Alternative Clients for Linux][79].
|
||||
|
||||
#### Everdo
|
||||
|
||||
[Everdo][78] is a beautiful, security-conscious, low-friction Getting-Things-Done app productivity app for handling to-dos and other note types. If Evernote comes off to you in an unpleasant way, Everdo is a perfect alternative.
|
||||
|
||||
[**Download Everdo for Ubuntu][80]
|
||||
|
||||
#### Taskwarrior
|
||||
|
||||
[Taskwarrior][81] is an open source and cross-platform command line app for managing tasks. It is famous for its speed and distraction-free environment.
|
||||
|
||||
Install **Taskwarrior** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install taskwarrior
|
||||
|
||||
```
|
||||
|
||||
### Video Players
|
||||
|
||||
#### Banshee
|
||||
|
||||
[Banshee][82] is an open source multi-format-supporting media player that was first developed in 2005 and has only been getting better since.
|
||||
|
||||
Install **Banshee** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:banshee-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install banshee
|
||||
|
||||
```
|
||||
|
||||
#### VLC
|
||||
|
||||
[VLC][83] is my favourite video player and it’s so awesome that it can play almost any audio and video format you throw at it. You can also use it to play internet radio, record desktop sessions, and stream movies online.
|
||||
|
||||
Install **VLC** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:videolan/stable-daily
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install vlc
|
||||
|
||||
```
|
||||
|
||||
#### Kodi
|
||||
|
||||
[Kodi][84] is among the world’s most famous media players and it comes as a full-fledged media centre app for playing all things media whether locally or remotely.
|
||||
|
||||
Install **Kodi** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install software-properties-common
|
||||
$ sudo add-apt-repository ppa:team-xbmc/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kodi
|
||||
|
||||
```
|
||||
|
||||
#### SMPlayer
|
||||
|
||||
[SMPlayer][85] is a GUI for the award-winning **MPlayer** and it is capable of handling all popular media formats; coupled with the ability to stream from YouTube, Chromcast, and download subtitles.
|
||||
|
||||
Install **SMPlayer** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:rvm/smplayer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install smplayer
|
||||
|
||||
```
|
||||
|
||||
### Virtualization Tools
|
||||
|
||||
#### VirtualBox
|
||||
|
||||
[VirtualBox][86] is an open source app created for general-purpose OS virtualization and it can be run on servers, desktops, and embedded systems.
|
||||
|
||||
Install **VirtualBox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install virtualbox-5.2
|
||||
$ virtualbox
|
||||
|
||||
```
|
||||
|
||||
#### VMWare
|
||||
|
||||
[VMware][87] is a digital workspace that provides platform virtualization and cloud computing services to customers and is reportedly the first to successfully virtualize x86 architecture systems. One of its products, VMware workstations allows users to run multiple OSes in a virtual memory.
|
||||
|
||||
For installation, read our article “[How to Install VMware Workstation Pro on Ubuntu][88]“.
|
||||
|
||||
### Web Browsers
|
||||
|
||||
#### Chrome
|
||||
|
||||
[Google Chrome][89] is undoubtedly the most popular browser. Known for its speed, simplicity, security, and beauty following Google’s Material Design trend, Chrome is a browser that web developers cannot do without. It is also free to use and open source.
|
||||
|
||||
Install **Google Chrome** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
|
||||
$ sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install google-chrome-stable
|
||||
|
||||
```
|
||||
|
||||
#### Firefox
|
||||
|
||||
[Firefox Quantum][90] is a beautiful, speed, task-ready, and customizable browser capable of any browsing task that you throw at it. It is also free, open source, and packed with developer-friendly tools that are easy for even beginners to get up and running with.
|
||||
|
||||
Install **Firefox Quantum** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:mozillateam/firefox-next
|
||||
$ sudo apt update && sudo apt upgrade
|
||||
$ sudo apt install firefox
|
||||
|
||||
```
|
||||
|
||||
#### Vivaldi
|
||||
|
||||
[Vivaldi][91] is a free and open source Chrome-based project that aims to perfect Chrome’s features with a couple of more feature additions. It is known for its colourful panels, memory-friendly performance, and flexibility.
|
||||
|
||||
[**Download Vivaldi for Ubuntu][91]
|
||||
|
||||
That concludes our list for today. Did I skip a famous title? Tell me about it in the comments section below.
|
||||
|
||||
Don’t forget to share this post and to subscribe to our newsletter to get the latest publications from FossMint.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.fossmint.com/most-used-linux-applications/
|
||||
|
||||
作者：[Martins D. Okoi][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.fossmint.com/author/dillivine/
|
||||
[1]:https://plus.google.com/share?url=https://www.fossmint.com/most-used-linux-applications/ (Share on Google+)
|
||||
[2]:https://www.linkedin.com/shareArticle?mini=true&url=https://www.fossmint.com/most-used-linux-applications/ (Share on LinkedIn)
|
||||
[3]:https://www.fossmint.com/awesome-linux-software/
|
||||
[4]:https://rsync.samba.org/
|
||||
[5]:https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/
|
||||
[6]:https://github.com/teejee2008/timeshift
|
||||
[7]:https://deluge-torrent.org/
|
||||
[8]:https://www.qbittorrent.org/
|
||||
[9]:https://transmissionbt.com/
|
||||
[10]:https://www.dropbox.com/
|
||||
[11]:https://www.google.com/drive/
|
||||
[12]:https://www.fossmint.com/best-google-drive-clients-for-linux/
|
||||
[13]:https://mega.nz/
|
||||
[14]:https://mega.nz/sync!linux
|
||||
[15]:https://www.vim.org/
|
||||
[16]:https://www.gnu.org/s/emacs/
|
||||
[17]:https://www.nano-editor.org/
|
||||
[18]:https://aria2.github.io/
|
||||
[19]:http://ugetdm.com/
|
||||
[20]:http://xdman.sourceforge.net/
|
||||
[21]:https://www.thunderbird.net/
|
||||
[22]:https://github.com/GNOME/geary
|
||||
[23]:https://github.com/GNOME/evolution
|
||||
[24]:https://www.gnucash.org/
|
||||
[25]:https://kmymoney.org/
|
||||
[26]:https://www.eclipse.org/ide/
|
||||
[27]:https://www.tecmint.com/install-eclipse-oxygen-ide-in-ubuntu-debian/
|
||||
[28]:https://netbeans.org/
|
||||
[29]:https://www.tecmint.com/install-netbeans-ide-in-ubuntu-debian-linux-mint/
|
||||
[30]:http://brackets.io/
|
||||
[31]:https://ide.atom.io/
|
||||
[32]:http://lighttable.com/
|
||||
[33]:https://code.visualstudio.com/
|
||||
[34]:https://code.visualstudio.com/download
|
||||
[35]:https://www.pidgin.im/
|
||||
[36]:https://www.skype.com/
|
||||
[37]:https://wiki.gnome.org/Apps/Empathy
|
||||
[38]:https://www.clamav.net/
|
||||
[39]:https://dave-theunsub.github.io/clamtk/
|
||||
[40]:https://github.com/linuxmint/cinnamon-desktop
|
||||
[41]:https://mate-desktop.org/
|
||||
[42]:https://www.gnome.org/
|
||||
[43]:https://www.kde.org/plasma-desktop
|
||||
[44]:https://github.com/nzjrs/gnome-tweak-tool
|
||||
[45]:https://github.com/oguzhaninan/Stacer
|
||||
[46]:https://www.bleachbit.org/
|
||||
[47]:https://www.bleachbit.org/download
|
||||
[48]:https://github.com/GNOME/gnome-terminal
|
||||
[49]:https://konsole.kde.org/
|
||||
[50]:https://gnometerminator.blogspot.com/p/introduction.html
|
||||
[51]:http://guake-project.org/
|
||||
[52]:https://ardour.org/
|
||||
[53]:https://www.audacityteam.org/
|
||||
[54]:https://www.gimp.org/
|
||||
[55]:https://krita.org/en/
|
||||
[56]:https://www.lwks.com/
|
||||
[57]:https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206
|
||||
[58]:https://www.openshot.org/
|
||||
[59]:http://www.pitivi.org/
|
||||
[60]:https://wiki.gnome.org/Apps/Rhythmbox
|
||||
[61]:https://gnumdk.github.io/lollypop-web/
|
||||
[62]:https://amarok.kde.org/en
|
||||
[63]:https://www.clementine-player.org/
|
||||
[64]:https://cmus.github.io/
|
||||
[65]:https://www.calligra.org/tour/calligra-suite/
|
||||
[66]:https://www.libreoffice.org/
|
||||
[67]:https://www.wps.com/
|
||||
[68]:http://wps-community.org/downloads
|
||||
[69]:http://shutter-project.org/
|
||||
[70]:https://launchpad.net/kazam
|
||||
[71]:https://gitlab.gnome.org/GNOME/gnome-screenshot
|
||||
[72]:http://www.maartenbaert.be/simplescreenrecorder/
|
||||
[73]:http://recordmydesktop.sourceforge.net/about.php
|
||||
[74]:https://atom.io/
|
||||
[75]:https://www.sublimetext.com/
|
||||
[76]:https://www.geany.org/
|
||||
[77]:https://wiki.gnome.org/Apps/Gedit
|
||||
[78]:https://everdo.net/
|
||||
[79]:https://www.fossmint.com/evernote-alternatives-for-linux/
|
||||
[80]:https://everdo.net/linux/
|
||||
[81]:https://taskwarrior.org/
|
||||
[82]:http://banshee.fm/
|
||||
[83]:https://www.videolan.org/
|
||||
[84]:https://kodi.tv/
|
||||
[85]:https://www.smplayer.info/
|
||||
[86]:https://www.virtualbox.org/wiki/VirtualBox
|
||||
[87]:https://www.vmware.com/
|
||||
[88]:https://www.tecmint.com/install-vmware-workstation-in-linux/
|
||||
[89]:https://www.google.com/chrome/
|
||||
[90]:https://www.mozilla.org/en-US/firefox/
|
||||
[91]:https://vivaldi.com/
|
||||
@ -0,0 +1,77 @@
|
||||
Distrochooser Helps Linux Beginners To Choose A Suitable Linux Distribution
|
||||
======
|
||||
|
||||
Howdy Linux newbies! Today, I have come up with a good news for you!! You might wondering how to choose a suitable Linux distribution for you. Of course, you might already have consulted some Linux experts to help you to select a Linux distribution for your needs. And some of you might have googled and gone through various resources, Linux forums, websites and blogs in the pursuit of finding perfect distro. Well, you need not to do that anymore. Meet **Distrochooser** , a website that helps you to easily find out a Linux distribution.
|
||||
|
||||
### How Distrochooser will help Linux beginners choose a suitable Linux distribution?
|
||||
|
||||
The Distrochooser will ask you a series of questions and suggests you different suitable Linux distributions to try, based on your answers. Excited? Great! Let us go ahead and see how to find out a suitable Linux distribution. Click on the following link to get started.
|
||||
|
||||
![][2]
|
||||
|
||||
You will be now redirected to Distrochooser home page where a small test is awaiting for you to enroll.
|
||||
|
||||
|
||||
You need to answer a series of questions (16 questions to be precise). Both single choice and multiple choice questions are provided there. Here are the complete list of questions.
|
||||
|
||||
1. Software: Use case
|
||||
2. Computer knowledge
|
||||
3. Linux Knowledge
|
||||
4. Installation: Presets
|
||||
5. Installation: Live-Test needed?
|
||||
6. Installation: Hardware support
|
||||
7. Configuration: Help source
|
||||
8. Distributions: User experience concept
|
||||
9. Distributions: Price
|
||||
10. Distributions: Scope
|
||||
11. Distributions: Ideology
|
||||
12. Distributions: Privacy
|
||||
13. Distributions: Preset themes, icons and wallpapers
|
||||
14. Distribution: Special features
|
||||
15. Software: Administration
|
||||
16. Software: Updates
|
||||
|
||||
|
||||
|
||||
Carefully read the questions and choose the appropriate answer(s) below the respective questions. Distrochooser gives more options to choose a near-perfect distribution.
|
||||
|
||||
* You can always skip questions,
|
||||
* You can always click on ‘get result’,
|
||||
* You can answer in arbitrary order,
|
||||
* You can delete answers at any time,
|
||||
* You can weight properties at the end of the test to emphasize what is important to you.
|
||||
|
||||
|
||||
|
||||
After choosing the answer(s) for a question, click **Proceed** to move to the next question. Once you are done, click on **Get result** button. You can also clear the selection at any time by clicking on the **“Clear”** button below the answers.
|
||||
|
||||
### Results?
|
||||
|
||||
I didn’t believe Distrochooser will exactly find what I am looking for. Oh boy, I was wrong! To my surprise, it did indeed a good job. The results were almost accurate to me. I was expecting Arch Linux in the result and indeed it was my top recommendation, followed by 11 other recommendations such as NixOS, Void Linux, Qubes OS, Scientific Linux, Devuan, Gentoo Linux, Bedrock Linux, Slackware, CentOS, Linux from scratch and Redhat Enterprise Linux. Totally, I got 12 recommendations and each result is very detailed along with distribution’s description and home page link for each distribution.
|
||||
|
||||
|
||||
|
||||
I posted Distrochooser link on Reddit and 80% of the users could be able to find suitable Linux distribution for them. However, I won’t claim Distrochooser alone is enough to find good results for everyone. Some users disappointed about the survey result and the result wasn’t even close to what they use or want to use. So, I strongly recommend you to consult other Linux experts, websites, forums before trying any Linux. You can read the full Reddit discussion [**here**][3].
|
||||
|
||||
What are you waiting for? Go to the Distrochooser site and choose a suitable Linux distribution for you.
|
||||
|
||||
And, that’s all for now, folks. More good stuffs to come. Stay tuned!
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/distrochooser-helps-linux-beginners-to-choose-a-suitable-linux-distribution/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.ostechnix.com/author/sk/
|
||||
[2]:https://distrochooser.de/en
|
||||
[3]:https://www.reddit.com/r/linux/comments/93p6az/distrochooser_helps_linux_beginners_to_choose_a/
|
||||
@ -0,0 +1,143 @@
|
||||
Top 5 CAD Software Available for Linux in 2018
|
||||
======
|
||||
[Computer Aided Design (CAD)][1] is an essential part of many streams of engineering. CAD is professionally used is architecture, auto parts design, space shuttle research, aeronautics, bridge construction, interior design, and even clothing and jewelry.
|
||||
|
||||
A number of professional grade CAD software like SolidWorks and Autodesk AutoCAD are not natively supported on the Linux platform. So today we will be having a look at the top CAD software available for Linux. Let’s dive right in.
|
||||
|
||||
### Best CAD Software available for Linux
|
||||
|
||||
![CAD Software for Linux][2]
|
||||
|
||||
Before you see the list of CAD software for Linux, you should keep one thing in mind that not all the applications listed here are open source. We included some non-FOSS CAD software to help average Linux user.
|
||||
|
||||
Installation instructions of Ubuntu-based Linux distributions have been provided. You may check the respective websites to learn the installation procedure for other distributions.
|
||||
|
||||
The list is not any specific order. CAD application at number one should not be considered better than the one at number three and so on.
|
||||
|
||||
#### 1\. FreeCAD
|
||||
|
||||
For 3D Modelling, FreeCAD is an excellent option which is both free (beer and speech) and open source. FreeCAD is built with keeping mechanical engineering and product design as target purpose. FreeCAD is multiplatform and is available on Windows, Mac OS X+ along with Linux.
|
||||
|
||||
![freecad][3]
|
||||
|
||||
Although FreeCAD has been the choice of many Linux users, it should be noted that FreeCAD is still on version 0.17 and therefore, is not suitable for major deployment. But the development has picked up pace recently.
|
||||
|
||||
[FreeCAD][4]
|
||||
|
||||
FreeCAD does not focus on direct 2D drawings and animation of organic shapes but it’s great for design related to mechanical engineering. FreeCAD version 0.15 is available in the Ubuntu repositories. You can install it by running the below command.
|
||||
```
|
||||
sudo apt install freecad
|
||||
|
||||
```
|
||||
|
||||
To get newer daily builds (0.17 at the moment), open a terminal (ctrl+alt+t) and run the commands below one by one.
|
||||
```
|
||||
sudo add-apt-repository ppa:freecad-maintainers/freecad-daily
|
||||
|
||||
sudo apt update
|
||||
|
||||
sudo apt install freecad-daily
|
||||
|
||||
```
|
||||
|
||||
#### 2\. LibreCAD
|
||||
|
||||
LibreCAD is a free, opensource, 2D CAD solution. Generally, CAD tends to be a resource-intensive task, and if you have a rather modest hardware, then I’d suggest you go for LibreCAD as it is really lightweight in terms of resource usage. LibreCAD is a great candidate for geometric constructions.
|
||||
|
||||
![librecad][5]
|
||||
As a 2D tool, LibreCAD is good but it cannot work on 3D models and renderings. It might be unstable at times but it has a dependable autosave which won’t let your work go wasted.
|
||||
|
||||
[LibreCAD][6]
|
||||
|
||||
You can install LibreCAD by running the following command
|
||||
```
|
||||
sudo apt install librecad
|
||||
|
||||
```
|
||||
|
||||
#### 3\. OpenSCAD
|
||||
|
||||
OpenSCAD is a free 3D CAD software. OpenSCAD is very lightweight and flexible. OpenSCAD is not interactive. You need to ‘program’ the model and OpenSCAD interprets that code to render a visual model. It is a compiler in a sense. You cannot draw the model. You describe the model.
|
||||
|
||||
![openscad][7]
|
||||
|
||||
OpenSCAD is the most complicated tool on this list but once you get to know it, it provides an enjoyable work experience.
|
||||
|
||||
[OpenSCAD][8]
|
||||
|
||||
You can use the following commands to install OpenSCAD.
|
||||
```
|
||||
sudo apt-get install openscad
|
||||
|
||||
```
|
||||
|
||||
#### 4\. BRL-CAD
|
||||
|
||||
BRL-CAD is one of the oldest CAD tools out there. It also has been loved by Linux/UNIX users as it aligns itself with *nix philosophies of modularity and freedom.
|
||||
|
||||
![BRL-CAD rendering by Sean][9]
|
||||
|
||||
BRL-CAD was started in 1979, and it is still developed actively. Now, BRL-CAD is not AutoCAD but it is still a great choice for transport studies such as thermal and ballistic penetration. BRL-CAD underlies CSG instead of boundary representation. You might need to keep that in mind while opting for BRL-CAD. You can download BRL-CAD from its official website.
|
||||
|
||||
[BRL-CAD][10]
|
||||
|
||||
#### 5\. DraftSight (not open source)
|
||||
|
||||
If You’re used to working on AutoCAD, then DraftSight would be the perfect alternative for you.
|
||||
|
||||
DraftSight is a great CAD tool available on Linux. It has a rather similar workflow to AutoCAD, which makes migrating easier. It even provides a similar look and feel. DrafSight is also compatible with the .dwg file format of AutoCAD. But DrafSight is a 2D CAD software. It does not support 3D CAD as of yet.
|
||||
|
||||
![draftsight][11]
|
||||
|
||||
Although DrafSight is a commercial software with a starting price of $149. A free version is also made available on the[DraftSight website][12]. You can download the .deb package and install it on Ubuntu based distributions. need to register your free copy using your email ID to start using DraftSight.
|
||||
|
||||
[DraftSight][12]
|
||||
|
||||
#### Honorary mentions
|
||||
|
||||
* With a huge growth in cloud computing technologies, cloud CAD solutions like [OnShape][13] have been getting popular day by day.
|
||||
* [SolveSpace][14] is another open-source project worth mentioning. It supports 3D modeling.
|
||||
* Siemens NX is an industrial grade CAD solution available on Windows, Mac OS and Linux, but it is ridiculously expensive, so omitted in this list.
|
||||
* Then you have [LeoCAD][15], which is a CAD software where you use LEGO blocks to build stuff. What you do with this information is up to you.
|
||||
|
||||
|
||||
|
||||
#### CAD on Linux, in my opinion
|
||||
|
||||
Although gaming on Linux has picked up, I always tell my hardcore gaming friends to stick to Windows. Similarly, if You are an engineering student with CAD in your curriculum, I’d recommend that you use the software that your college prescribes (AutoCAD, SolidEdge, Catia), which generally tend to run on Windows only.
|
||||
|
||||
And for the advanced professionals, these tools are simply not up to the mark when we’re talking about industry standards.
|
||||
|
||||
For those of you thinking about running AutoCAD in WINE, although some older versions of AutoCAD can be installed on WINE, they simply do not perform, with glitches and crashes ruining the experience.
|
||||
|
||||
That being said, I highly respect the work that has been put by the developers of the above-listed software. They have enriched the FOSS world. And it’s great to see software like FreeCAD developing with an accelerated pace in the recent years.
|
||||
|
||||
Well, that’s it for today. Do share your thoughts with us using the comments section below and don’t forget to share this article. Cheers.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/cad-software-linux/
|
||||
|
||||
作者：[Aquil Roshan][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://itsfoss.com/author/aquil/
|
||||
[1]:https://en.wikipedia.org/wiki/Computer-aided_design
|
||||
[2]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/cad-software-linux.jpeg
|
||||
[3]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/freecad.jpg
|
||||
[4]:https://www.freecadweb.org/
|
||||
[5]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/librecad.jpg
|
||||
[6]:https://librecad.org/
|
||||
[7]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/openscad.jpg
|
||||
[8]:http://www.openscad.org/
|
||||
[9]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/brlcad.jpg
|
||||
[10]:https://brlcad.org/
|
||||
[11]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/07/draftsight.jpg
|
||||
[12]:https://www.draftsight2018.com/
|
||||
[13]:https://www.onshape.com/
|
||||
[14]:http://solvespace.com/index.pl
|
||||
[15]:https://www.leocad.org/
|
||||
@ -0,0 +1,136 @@
|
||||
10 Popular Windows Apps That Are Also Available on Linux
|
||||
======
|
||||
|
||||
Looking back, 2018 has been a good year for the Linux community. Many applications that were only available on Windows and/or Mac are available on the Linux platform with little to no hassle. Hats off to [Snap][3] and [Flatpak][4] technologies which have helped bring many “restricted” apps to Linux users.
|
||||
|
||||
**Read Also** : [All AWESOME Linux Applications and Tools][5]
|
||||
|
||||
Today, we bring you a list of famous Windows applications that you don’t need to find alternatives for because they are already available on Linux.
|
||||
|
||||
### 1\. Skype
|
||||
|
||||
Arguably the world’s most loved VoIP application, **Skype** provides excellent video and voice call quality coupled with other features like the option to make local and international calls, landline calls, instant messaging, emojis, etc.
|
||||
```
|
||||
$ sudo snap install skype --classic
|
||||
|
||||
```
|
||||
|
||||
### 2\. Spotify
|
||||
|
||||
**Spotify** is the most popular music streaming platform and for a long time, Linux users needed to use scripts and techy hacks to set up the app on their machines, Thanks to snap tech, installing and using Spotify is as easy as clicking a button.
|
||||
```
|
||||
$ sudo snap install spotify
|
||||
|
||||
```
|
||||
|
||||
### 3\. Minecraft
|
||||
|
||||
**Minecraft** is a game that has proven to be awesome irrespective of the year. What’s cooler about it is the fact that it is consistently maintained. If you don’t know Mincraft, it is an adventure game that allows you to use building blocks to create virtually anything you can craft in an infinite and unbounded virtual world.
|
||||
```
|
||||
$ sudo snap install minecraft
|
||||
|
||||
```
|
||||
|
||||
### 4\. JetBrains Dev Suite
|
||||
|
||||
**JetBrains** is well-known for its premium suite of development IDEs and their most popular app titles are available for use on Linux without any hassle.
|
||||
|
||||
#### Install IDEA Community – Java IDE
|
||||
```
|
||||
$ sudo snap install intellij-idea-community --classic
|
||||
|
||||
```
|
||||
|
||||
#### Install PyCharm EDU – Python IDE
|
||||
```
|
||||
$ sudo snap install pycharm-educational --classic
|
||||
|
||||
```
|
||||
|
||||
#### Install PhpStorm – PHP IDE
|
||||
```
|
||||
$ sudo snap install phpstorm --classic
|
||||
|
||||
```
|
||||
|
||||
#### Install WebStorm – JavaScript IDE
|
||||
```
|
||||
$ sudo snap install webstorm --classic
|
||||
|
||||
```
|
||||
|
||||
#### Install RubyMine – Ruby and Rails IDE
|
||||
```
|
||||
$ sudo snap install rubymine --classic
|
||||
|
||||
```
|
||||
|
||||
### 5\. PowerShell
|
||||
|
||||
**PowerShell** is a platform for managing PC automation and configurations and it offers a command-line shell with relevant scripting languages. If you thought that it was available on only Windows then think again.
|
||||
```
|
||||
$ sudo snap install powershell --classic
|
||||
|
||||
```
|
||||
|
||||
### 6\. Ghost
|
||||
|
||||
**Ghost** is a modern desktop app that enables users to manage multiple Ghost blogs, magazines, online publications, etc. in a distraction-free environment.
|
||||
```
|
||||
$ sudo snap install ghost-desktop
|
||||
|
||||
```
|
||||
|
||||
### 7\. MySQL Workbench
|
||||
|
||||
**MySQL Workbench** is a GUI app for designing and managing databases with integrated SQL functionalities.
|
||||
|
||||
[**Download MySQL Workbench][6]
|
||||
|
||||
### 8\. Adobe App Suite via PlayOnLinux
|
||||
|
||||
You might have missed the article we published on [PlayOnLinux][7] so here is another chance to check it out.
|
||||
|
||||
PlayOnLinux is basically an improved implementation of **wine** that allows users to install Adobe’s creative cloud apps more easily. Mind you, the trial and subscription limits still apply.
|
||||
|
||||
[**How to Use PlayOnLinux][8]
|
||||
|
||||
### 9\. Slack
|
||||
|
||||
Reportedly the most used team communication software among developers and project managers, **Slack** offers workspaces with various document and messages management functionalities that everybody can’t seem to get enough of.
|
||||
```
|
||||
$ sudo snap install slack --classic
|
||||
|
||||
```
|
||||
|
||||
### 10\. Blender
|
||||
|
||||
**Blender** is among the most popular application for 3D creation. It is free, open-source, and has support for the entirety of the 3D pipeline.
|
||||
```
|
||||
$ sudo snap install blender --classic
|
||||
|
||||
```
|
||||
|
||||
That’s it! We know the ultimate list goes on but we can only list so much. Did we omit any applications you think should have made it to the list? Add your suggestions in the comments section below.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.fossmint.com/install-popular-windows-apps-on-linux/
|
||||
|
||||
作者：[Martins D. Okoi;View All Posts][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.fossmint.com/author/dillivine/
|
||||
[1]:https://plus.google.com/share?url=https://www.fossmint.com/install-popular-windows-apps-on-linux/ (Share on Google+)
|
||||
[2]:https://www.linkedin.com/shareArticle?mini=true&url=https://www.fossmint.com/install-popular-windows-apps-on-linux/ (Share on LinkedIn)
|
||||
[3]:https://www.fossmint.com/what-are-ubuntu-snaps-and-how-are-they-important/
|
||||
[4]:https://www.fossmint.com/install-flatpak-in-linux/
|
||||
[5]:https://www.fossmint.com/awesome-linux-software/
|
||||
[6]:https://dev.mysql.com/downloads/workbench/
|
||||
[7]:https://www.fossmint.com/playonlinux-another-open-source-solution-for-linux-game-lovers/
|
||||
[8]:https://www.fossmint.com/adobe-creative-cloud-install-adobe-apps-on-linux/
|
||||
@ -1,3 +1,5 @@
|
||||
pinewall translating
|
||||
|
||||
How To Switch Between Different Versions Of Commands In Linux
|
||||
======
|
||||
|
||||
|
||||
@ -0,0 +1,112 @@
|
||||
MPV Player: A Minimalist Video Player for Linux
|
||||
======
|
||||
MPV is an open source, cross platform video player that comes with a minimalist GUI and feature rich command line version.
|
||||
|
||||
VLC is probably the best video player for Linux or any other operating system. I have been using VLC for years and it is still my favorite.
|
||||
|
||||
However, lately, I am more inclined towards minimalist applications with a clean UI. This is how came across MPV. I loved it so much that I added it in the list of [best Ubuntu applications][1].
|
||||
|
||||
[MPV][2] is an open source video player available for Linux, Windows, macOS, BSD and Android. It is actually a fork of [MPlayer][3].
|
||||
|
||||
The graphical user interface is sleek and minimalist.
|
||||
|
||||
![MPV Player Interface in Linux][4]
|
||||
MPV Player
|
||||
|
||||
### MPV Features
|
||||
|
||||
MPV has all the features required from a standard video player. You can play a variety of videos and control the playback with usual shortcuts.
|
||||
|
||||
* Minimalist GUI with only the necessary controls.
|
||||
* Video codecs support.
|
||||
* High quality video output and GPU video decoding.
|
||||
* Supports subtitles.
|
||||
* Can play YouTube and other streaming videos through the command line.
|
||||
* CLI version of MPV can be embedded in web and other applications.
|
||||
|
||||
|
||||
|
||||
Though MPV player has a minimal UI with limited options, don’t underestimate its capabilities. Its main power lies in the command line version.
|
||||
|
||||
Just type the command mpv –list-options and you’ll see that it provides 447 different kind of options. But this article is not about utilizing the advanced settings of MPV. Let’s see how good it is as a regular desktop video player.
|
||||
|
||||
### Installing MPV in Linux
|
||||
|
||||
MPV is a popular application and it should be found in the default repositories of most Linux distributions. Just look for it in the Software Center application.
|
||||
|
||||
I can confirm that it is available in Ubuntu’s Software Center. You can install it from there or simply use the following command:
|
||||
```
|
||||
sudo apt install mpv
|
||||
|
||||
```
|
||||
|
||||
You can find installation instructions for other platforms on [MPV website][5].
|
||||
|
||||
### Using MPV Video Player
|
||||
|
||||
Once installed, you can open a video file with MPV by right-clicking and choosing MPV.
|
||||
|
||||
![MPV Player Interface][6]
|
||||
MPV Player Interface
|
||||
|
||||
The interface has only a control panel that is only visible when you hover your mouse on the player. As you can see, the control panel provides you the option to pause/play, change track, change audio track, subtitles and switch to full screen.
|
||||
|
||||
MPV’s default size depends upon the quality of video you are playing. For a 240p video, the application video will be small while as 1080p video will result in almost full screen app window size on a Full-HD screen. You can always double click on the player to make it full screen irrespective of the video size.
|
||||
|
||||
#### The subtitle struggle
|
||||
|
||||
If your video has a subtitle file, MPV will [automatically play subtitles][7] and you can choose to disable it. However, if you want to use an external subtitle file, it’s not that available directly from the player.
|
||||
|
||||
You can rename the additional subtitle file exactly the same as the name of the video file and keep it in the same folder as the video file. MPV should now play your subtitles.
|
||||
|
||||
An easier option to play external subtitles is to simply drag and drop into the player.
|
||||
|
||||
#### Playing YouTube and other online video content
|
||||
|
||||
To play online videos, you’ll have to use the command line version of MPV.
|
||||
|
||||
Open a terminal and use it in the following fashion:
|
||||
```
|
||||
mpv <URL_of_Video>
|
||||
|
||||
```
|
||||
|
||||
![Playing YouTube videos on Linux desktop using MPV][8]
|
||||
Playing YouTube videos with MPV
|
||||
|
||||
I didn’t find playing YouTube videos in MPV player a pleasant experience. It kept on buffering and that was utter frustrating.
|
||||
|
||||
#### Should you use MPV player?
|
||||
|
||||
That depends on you. If you like to experiment with applications, you should give MPV a go. Otherwise, the default video player and VLC are always good enough.
|
||||
|
||||
Earlier when I wrote about [Sayonara][9], I wasn’t sure if people would like an obscure music player over the popular ones but it was loved by It’s FOSS readers.
|
||||
|
||||
Try MPV and see if it is something you would like to use as your default video player.
|
||||
|
||||
If you liked MPV but want slightly more features on the graphical interface, I suggest using [GNOME MPV Player][10].
|
||||
|
||||
Have you used MPV video player? How was your experience with it? What you liked or disliked about it? Do share your views in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/mpv-video-player/
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/abhishek/
|
||||
[1]:https://itsfoss.com/best-ubuntu-apps/
|
||||
[2]:https://mpv.io/
|
||||
[3]:http://www.mplayerhq.hu/design7/news.html
|
||||
[4]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/mpv-player.jpg
|
||||
[5]:https://mpv.io/installation/
|
||||
[6]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/mpv-player-interface.png
|
||||
[7]:https://itsfoss.com/how-to-play-movie-with-subtitles-on-samsung-tv-via-usb/
|
||||
[8]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/play-youtube-videos-on-mpv-player.jpeg
|
||||
[9]:https://itsfoss.com/sayonara-music-player/
|
||||
[10]:https://gnome-mpv.github.io/
|
||||
@ -1,203 +0,0 @@
|
||||
translating by ypingcn
|
||||
|
||||
Tips for using the top command in Linux
|
||||
======
|
||||
|
||||
|
||||
|
||||
Trying to find out what's running on your machine—and which process is using up all your memory and making things slllooowwww—is a task served well by the utility `top`.
|
||||
|
||||
`top` is an extremely useful program that acts similar to Windows Task Manager or MacOS's Activity Monitor. Running `top` on your *nix machine will show you a live, running view of the process running on your system.
|
||||
```
|
||||
$ top
|
||||
|
||||
```
|
||||
|
||||
Depending on which version of `top` you're running, you'll get something that looks like this:
|
||||
```
|
||||
top - 08:31:32 up 1 day, 4:09, 0 users, load average: 0.20, 0.12, 0.10
|
||||
|
||||
Tasks: 3 total, 1 running, 2 sleeping, 0 stopped, 0 zombie
|
||||
|
||||
%Cpu(s): 0.5 us, 0.3 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
|
||||
|
||||
KiB Mem: 4042284 total, 2523744 used, 1518540 free, 263776 buffers
|
||||
|
||||
KiB Swap: 1048572 total, 0 used, 1048572 free. 1804264 cached Mem
|
||||
|
||||
|
||||
|
||||
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
|
||||
|
||||
1 root 20 0 21964 3632 3124 S 0.0 0.1 0:00.23 bash
|
||||
|
||||
193 root 20 0 123520 29636 8640 S 0.0 0.7 0:00.58 flask
|
||||
|
||||
195 root 20 0 23608 2724 2400 R 0.0 0.1 0:00.21 top
|
||||
|
||||
```
|
||||
|
||||
Your version of `top` may look different from this, particularly in the columns that are displayed.
|
||||
|
||||
### How to read the output
|
||||
|
||||
You can tell what you're running based on the output, but trying to interpret the results can be slightly confusing.
|
||||
|
||||
The first few lines contain a bunch of statistics (the details) followed by a table with a list of results (the list). Let's start with the latter.
|
||||
|
||||
#### The list
|
||||
|
||||
These are the processes that are running on the system. By default, they are ordered by CPU usage in descending order. This means the items at the top of the list are using more CPU resources and causing more load on your system. They are literally the "top" processes by resource usage. You have to admit, it's a clever name.
|
||||
|
||||
The `COMMAND` column on the far right reports the name of the process (the command you ran to start them). In this example, they are `bash` (a command interpreter we're running `top` in), `flask` (a web micro-framework written in Python), and `top` itself.
|
||||
|
||||
The other columns provide useful information about the processes:
|
||||
|
||||
* `PID`: the process id, a unique identifier for addressing the processes
|
||||
* `USER`: the user running the process
|
||||
* `PR`: the task's priority
|
||||
* `NI`: a nicer representation of the priority
|
||||
* `VIRT`: virtual memory size in KiB (kibibytes)*
|
||||
* `RES`: resident memory size in KiB* (the "physical memory" and a subset of VIRT)
|
||||
* `SHR`: shared memory size in KiB* (the "shared memory" and a subset of VIRT)
|
||||
* `S`: process state, usually **I** =idle, **R** =running, **S** =sleeping, **Z** =zombie, **T** or **t** =stopped (there are also other, less common options)
|
||||
* `%CPU`: Percentage of CPU usage since the last screen update
|
||||
* `%MEM`: percentage of `RES` memory usage since the last screen update
|
||||
* `TIME+`: total CPU time used since the process started
|
||||
* `COMMAND`: the command, as described above
|
||||
|
||||
|
||||
|
||||
*Knowing exactly what the `VIRT`, `RES`, and `SHR` values represent doesn't really matter in everyday operations. The important thing to know is that the process with the most `VIRT` is the process using the most memory. If you're in `top` because you're debugging why your computer feels like it's in a pool of molasses, the process with the largest `VIRT` number is the culprit. If you want to learn exactly what "shared" and "physical" memory mean, check out "Linux Memory Types" in the [top manual][1].
|
||||
|
||||
And, yes, I did mean to type kibibytes, not kilobytes. The 1,024 value that you normally call a kilobyte is actually a kibibyte. The Greek kilo ("χίλιοι") means thousand and means 1,000 of something (e.g., a kilometer is a thousand meters, a kilogram is a thousand grams). Kibi is a portmanteau of kilo and byte, and it means 1,024 bytes (or 210). But, because words are hard to say, many people say kilobyte when they mean 1,024 bytes. All this means is `top` is trying to use the proper terms here, so just go with it. #themoreyouknow 🌈.
|
||||
|
||||
#### A note on screen updates:
|
||||
|
||||
Live screen updates are one of the objectively **really cool things** Linux programs can do. This means they can update their own display in real time, so they appear animated. Even though they're using text. So cool! In our case, the time between updates is important, because some of our statistics (`%CPU` and `%MEM`) are based on the value since the last screen update.
|
||||
|
||||
And because we're running in a persistent application, we can press key commands to make live changes to settings or configurations (instead of, say, closing the application and running the application again with a different command-line flag).
|
||||
|
||||
Typing `h` invokes the "help" screen, which also shows the default delay (the time between screen updates). By default, this value is (around) three seconds, but you can change it by typing `d` (presumably for "delay") or `s` (probably for "screen" or "seconds").
|
||||
|
||||
#### The details
|
||||
|
||||
Above the list of processes, there's a whole bunch of other useful information. Some of these details may look strange and confusing, but once you take some time to step through each one, you'll see they're very useful stats to pull up in a pinch.
|
||||
|
||||
The first row contains general system information
|
||||
|
||||
* `top`: we're running `top`! Hi `top`!
|
||||
* `XX:YY:XX`: the time, updated every time the screen updates
|
||||
* `up` (then `X day, YY:ZZ`): the system's [uptime][2], or how much time has passed since the system turned on
|
||||
* `load average` (then three numbers): the [system load][3] over the last one, five, and 15 minutes, respectively
|
||||
|
||||
|
||||
|
||||
The second row (`Tasks`) shows information about the running tasks, and it's fairly self-explanatory. It shows the total number of processes and the number of running, sleeping, stopped, and zombie processes. This is literally a sum of the `S` (state) column described above.
|
||||
|
||||
The third row (`%Cpu(s)`) shows the CPU usage separated by types. The data are the values between screen refreshes. The values are:
|
||||
|
||||
* `us`: user processes
|
||||
* `sy`: system processes
|
||||
* `ni`: [nice][4] user processes
|
||||
* `id`: the CPU's idle time; a high idle time means there's not a lot going on otherwise
|
||||
* `wa`: wait time, or time spent waiting for I/O completion
|
||||
* `hi`: time spent waiting for hardware interrupts
|
||||
* `si`: time spent waiting for software interrupts
|
||||
* `st`: "time stolen from this VM by the hypervisor"
|
||||
|
||||
|
||||
|
||||
You can collapse the `Tasks` and `%Cpu(s)` rows by typing `t` (for "toggle").
|
||||
|
||||
The fourth (`KiB Mem`) and fifth rows (`KiB Swap`) provide information for memory and swap. These values are:
|
||||
|
||||
* `total`
|
||||
* `used`
|
||||
* `free`
|
||||
|
||||
|
||||
|
||||
But also:
|
||||
|
||||
* memory `buffers`
|
||||
* swap `cached Mem`
|
||||
|
||||
|
||||
|
||||
By default, they're listed in KiB, but pressing `E` (for "extend memory scaling") cycles through different values: kibibytes, mebibytes, gibibytes, tebibytes, pebibytes, and exbibytes. (That is, kilobytes, megabytes, gigabytes, terabytes, petabytes, and exabytes, but their "real names.")
|
||||
|
||||
The `top` user manual shows even more information about useful flags and configurations. To find the manual on your system, you can run `man top`. There are various websites that show an [HTML rendering of the manual][1], but note that these may be for a different version of top.
|
||||
|
||||
### Two top alternatives
|
||||
|
||||
You don't always have to use `top` to understand what's going on. Depending on your circumstances, other tools might help you diagnose issues, especially when you want a more graphical or specialized interface.
|
||||
|
||||
#### htop
|
||||
|
||||
`htop` is a lot like `top`, but it brings something extremely useful to the table: a graphical representation of CPU and memory use.
|
||||
|
||||
|
||||
|
||||
This is how the environment we examined in `top` looks in `htop`. The display is a lot simpler, but still rich in features.
|
||||
|
||||
Our task counts, load, uptime, and list of processes are still there, but we get a nifty, colorized, animated view of the CPU usage per core and a graph of memory usage.
|
||||
|
||||
Here's what the different colors mean (you can also get this information by pressing `h` for "help").
|
||||
|
||||
CPU task priorities or types:
|
||||
|
||||
* blue: low priority
|
||||
* green: normal priority
|
||||
* red: kernel tasks
|
||||
* blue: virtualized tasks
|
||||
* the value at end of the bar is the percentage of used CPU
|
||||
|
||||
|
||||
|
||||
Memory:
|
||||
|
||||
* green: used memory
|
||||
* blue: buffered memory
|
||||
* yellow: cached memory
|
||||
* the values at the end of the bar show the used and total memory
|
||||
|
||||
|
||||
|
||||
If colors aren't useful for you, you can run `htop -C` to disable them; instead `htop` will use different symbols to separate the CPU and memory types.
|
||||
|
||||
At the bottom, there's a useful display of active function keys that you can use to do things like filter results or change the sort order. Try out some of the commands to see what they do. Just be careful when trying out `F9`. This will bring up a list of signals that will kill (i.e., stop) a process. I would suggest exploring these options outside of a production environment.
|
||||
|
||||
The author of `htop`, Hisham Muhammad (and yes, it's called `htop` after Hisham) presented a [lightning talk][5] about `htop` at [FOSDEM 2018][6] in February. He explained how `htop` not only has neat graphics, but also surfaces more modern statistical information about processes that older monitoring utilities (like `top`) don't.
|
||||
|
||||
You can read more about `htop` on the [manual page][7] or the [htop website][8]. (Warning: the website contains an animated background of `htop`.)
|
||||
|
||||
#### docker stats
|
||||
|
||||
If you're working with Docker, you can run `docker stats` to generate a context-rich representation of what your containers are doing.
|
||||
|
||||
This can be more helpful than `top` because, instead of separating by processes, you are separating by container. This is especially useful when a container is slow, as seeing which container is using the most resources is quicker than running `top` and trying to map the process to the container.
|
||||
|
||||
The above explanations of acronyms and descriptors in `top` and `htop` should make it easy to understand the ones in `docker stats`. However, the [docker stats documentation][9] provides helpful descriptions of each column.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/top-tips-speed-up-computer
|
||||
|
||||
作者：[Katie McLaughlin][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/glasnt
|
||||
[1]:http://man7.org/linux/man-pages/man1/top.1.html
|
||||
[2]:https://en.wikipedia.org/wiki/Uptime
|
||||
[3]:https://en.wikipedia.org/wiki/Load_(computing)
|
||||
[4]:https://en.wikipedia.org/wiki/Nice_(Unix)#Etymology
|
||||
[5]:https://www.youtube.com/watch?v=L25waVhy78o
|
||||
[6]:https://fosdem.org/2018/schedule/event/htop/
|
||||
[7]:https://linux.die.net/man/1/htop
|
||||
[8]:https://hisham.hm/htop/index.php
|
||||
[9]:https://docs.docker.com/engine/reference/commandline/stats/
|
||||
@ -0,0 +1,84 @@
|
||||
translating by lujun9972
|
||||
How to Create M3U Playlists in Linux [Quick Tip]
|
||||
======
|
||||
**Brief: A quick tip on how to create M3U playlists in Linux terminal from unordered files to play them in a sequence.**
|
||||
|
||||
![Create M3U playlists in Linux Terminal][1]
|
||||
|
||||
I am a fan of foreign tv series and it’s not always easy to get them on DVD or on streaming services like [Netflix][2]. Thankfully, you can find some of them on YouTube and [download them from YouTube][3].
|
||||
|
||||
Now there comes a problem. Your files might not be sorted in a particular order. In GNU/Linux files are not naturally sort ordered by number sequencing so I had to make a .m3u playlist so [MPV video player][4] would play the videos in sequence and not out of sequence.
|
||||
|
||||
Also sometimes the numbers are in the middle or the end like ‘My Web Series S01E01.mkv’ as an example. The episode information here is in the middle of the filename, the ‘S01E01’ which tells us, humans, which is the first episode and which needs to come in next.
|
||||
|
||||
So what I did was to generate an m3u playlist in the video directory and tell MPV to play the .m3u playlist and it would take care of playing them in the sequence.
|
||||
|
||||
### What is an M3U file?
|
||||
|
||||
[M3U][5] is basically a text file that contains filenames in a specific order. When a player like MPV or VLC opens an M3U file, it tries to play the specified files in the given sequence.
|
||||
|
||||
### Creating M3U to play audio/video files in a sequence
|
||||
|
||||
In my case, I used the following command:
|
||||
```
|
||||
$/home/shirish/Videos/web-series-video/$ ls -1v |grep .mkv > /tmp/1.m3u && mv /tmp/1.m3u .
|
||||
|
||||
```
|
||||
|
||||
Let’s break it down a bit and see each bit as to what it means –
|
||||
|
||||
**ls -1v** = This is using the plain ls or listing entries in the directory. The -1 means list one file per line. while -v natural sort of (version) numbers within text
|
||||
|
||||
**| grep .mkv** = It’s basically telling `ls` to look for files which are ending in .mkv . It could be .mp4 or any other media file format that you want.
|
||||
|
||||
It’s usually a good idea to do a dry run by running the command on the console:
|
||||
```
|
||||
ls -1v |grep .mkv
|
||||
My Web Series S01E01 [Episode 1 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E02 [Episode 2 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E03 [Episode 3 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E04 [Episode 4 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E05 [Episode 5 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E06 [Episode 6 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E07 [Episode 7 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E08 [Episode 8 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
|
||||
```
|
||||
|
||||
This tells me that what I’m trying to do is correct. Now just have to make that the output is in the form of a .m3u playlist which is the next part.
|
||||
```
|
||||
ls -1v |grep .mkv > /tmp/web_playlist.m3u && mv /tmp/web_playlist.m3u .
|
||||
|
||||
```
|
||||
|
||||
This makes the .m3u generate in the current directory. The .m3u playlist is nothing but a .txt file with the same contents as above with the .m3u extension. You can edit it manually as well and add the exact filenames in an order you desire.
|
||||
|
||||
After that you just have to do something like this:
|
||||
```
|
||||
mpv web_playlist.m3u
|
||||
|
||||
```
|
||||
|
||||
The great thing about MPV and the playlists, in general, is that you don’t have to binge-watch. You can see however much you want to do in one sitting and see the rest in the next session or the session after that.
|
||||
|
||||
I hope to do articles featuring MPV as well as how to make mkv files embedding subtitles in a media file but that’s in the future.
|
||||
|
||||
Note: It’s FOSS doesn’t encourage piracy.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/create-m3u-playlist-linux/
|
||||
|
||||
作者：[Shirsh][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://itsfoss.com/author/shirish/
|
||||
[1]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/Create-M3U-Playlists.jpeg
|
||||
[2]:https://itsfoss.com/netflix-open-source-ai/
|
||||
[3]:https://itsfoss.com/download-youtube-linux/
|
||||
[4]:https://itsfoss.com/mpv-video-player/
|
||||
[5]:https://en.wikipedia.org/wiki/M3U
|
||||
@ -0,0 +1,74 @@
|
||||
Add YouTube Player Controls To Your Linux Desktop With browser-mpris2 (Chrome Extension)
|
||||
======
|
||||
A Unity feature that I miss (it only actually worked for a short while though) is automatically getting player controls in the Ubuntu Sound Indicator when visiting a website like YouTube in a web browser, so you could pause or stop the video directly from the top bar, as well as see the video / song information and a preview.
|
||||
|
||||
This Unity feature is long dead, but I was searching for something similar for Gnome Shell and I came across **[browser-mpris2][1], an extension that implements a MPRIS v2 interface for Google Chrome / Chromium, which currently only supports YouTube** , and I thought there might be some Linux Uprising readers who'll like this.
|
||||
|
||||
**The extension also works with Chromium-based web browsers like Opera and Vivaldi.**
|
||||
**
|
||||
** **browser-mpris2 also supports Firefox but since loading extensions via about:debugging is temporary, and this is needed for browser-mpris2, this article doesn't include Firefox instructions. The developer[intends][2] to submit the extension to the Firefox addons website in the future.**
|
||||
|
||||
**Using this Chrome extension you get YouTube media player controls (play, pause, stop and seeking) in MPRIS2-capable applets**. For example, if you use Gnome Shell, you get YouTube media player controls as a permanent notification or, you can use an extension like Media Player Indicator for this. In Cinnamon / Linux Mint with Cinnamon, it shows up in the Sound Applet.
|
||||
|
||||
**It didn't work for me on Unity** , I'm not sure why. I didn't try this extension with other MPRIS2-capable applets available in various desktop environments (KDE, Xfce, MATE, etc.). If you give it a try, let us know if it works with your desktop environment / MPRIS2 enabled applet.
|
||||
|
||||
Here is a screenshot with [Media Player Indicator][3] displaying information about the currently playing YouTube video, along with its controls (play/pause, stop and seeking), on Ubuntu 18.04 with Gnome Shell and Chromium browser:
|
||||
|
||||
|
||||
|
||||
And in Linux Mint 19 Cinnamon with its default sound applet and Chromium browser:
|
||||
|
||||
|
||||
|
||||
### How to install browser-mpris2 for Google Chrome / Chromium
|
||||
|
||||
**1\. Install Git if you haven't already.**
|
||||
|
||||
In Debian / Ubuntu / Linux Mint, use this command to install git:
|
||||
```
|
||||
sudo apt install git
|
||||
|
||||
```
|
||||
|
||||
**2\. Download and install the[browser-mpris2][1] required files.**
|
||||
|
||||
The commands below clone the browser-mpris2 Git repository and install the chrome-mpris2 file to `/usr/local/bin/` (run the "git clone..." command in a folder where you can continue to keep the browser-mpris2 folder because you can't remove it, as it will be used by Chrome / Chromium):
|
||||
```
|
||||
git clone https://github.com/otommod/browser-mpris2
|
||||
sudo install browser-mpris2/native/chrome-mpris2 /usr/local/bin/
|
||||
|
||||
```
|
||||
|
||||
**3\. Load the extension in Chrome / Chromium-based web browsers.**
|
||||
|
||||
|
||||
|
||||
Open Google Chrome, Chromium, Opera or Vivaldi web browsers, go to the Extensions page (enter `chrome://extensions` in the URL bar), enable `Developer mode` using the toggle available in the top right-hand side of the screen, then select `Load Unpacked` and select the chrome-mpris2 directory (make sure to not select a subfolder).
|
||||
|
||||
Copy the extension ID and save it because you'll need it later (it's something like: `emngjajgcmeiligomkgpngljimglhhii` but it's different for you so make sure to use the ID from your computer!) .
|
||||
|
||||
**4\. Run** `install-chrome.py` (from the `browser-mpris2/native` folder), specifying the extension id and chrome-mpris2 path.
|
||||
|
||||
Use this command in a terminal (replace `REPLACE-THIS-WITH-EXTENSION-ID` with the browser-mpris2 extension ID displayed under `chrome://extensions` from the previous step) to install this extension:
|
||||
```
|
||||
browser-mpris2/native/install-chrome.py REPLACE-THIS-WITH-EXTENSION-ID /usr/local/bin/chrome-mpris2
|
||||
|
||||
```
|
||||
|
||||
You only need to run this command once, there's no need to add it to startup or anything like that. Any YouTube video you play in Google Chrome or Chromium browsers should show up in whatever MPRISv2 applet you're using. There's no need to restart the web browser.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linuxuprising.com/2018/08/add-youtube-player-controls-to-your.html
|
||||
|
||||
作者：[Logix][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://plus.google.com/118280394805678839070
|
||||
[1]:https://github.com/otommod/browser-mpris2
|
||||
[2]:https://github.com/otommod/browser-mpris2/issues/11
|
||||
[3]:https://extensions.gnome.org/extension/55/media-player-indicator/
|
||||
@ -0,0 +1,74 @@
|
||||
Designing your garden with Edraw Max – FOSS adventures
|
||||
======
|
||||
|
||||
I watch a lot of [BBC Gardeners World][1], which gives me a lot of inspiration for making changes to my own garden. I tried looking for a free and open source program for designing gardens in the openSUSE [package search][2]. The only application that I found was Rosegarden, a MIDI and Audio Sequencer and Notation Editor. Using google, I found [Edraw Max][3], an all-in-one diagram software. This included a Floor planner, including templates for garden design. And there are download options for various Linux distributions, including openSUSE.
|
||||
|
||||
### Installation
|
||||
|
||||
You can download a 14-day free trial from the Edraw Max [website][4].
|
||||
|
||||
![][5]
|
||||
|
||||
The next thing to do, is use Dolphin and browse to your Downloads folder. Find the zipped package and double click it. Ark will automatically load it. Then click on the Extract button.
|
||||
|
||||
![][6]
|
||||
|
||||
Now you can press F4 in Dolphin to open the integrated terminal. If you type in the commands as listed on the Edraw website, the application will install without an issue.
|
||||
|
||||
![][7]
|
||||
|
||||
### Experience
|
||||
|
||||
From the application launcher (start menu), you can now type Edraw Max and launch the application. Go to New and then Floor Plan and click on Garden Design.
|
||||
|
||||
![][8]
|
||||
|
||||
On the left side, there is a side pane with a lot of elements that you can use for drawing (see picture below). Start with measuring your garden and with the walls, you can ‘draw’ the borders of your garden. On the right side, there is a side pane where you can adjust the properties of these elements. For instance you can edit the fill (color) of the element, the border (color) of the element and adjust the properties. I didn’t need the other parts of this right side pane (which included shadow, insert picture, layer, hyperlink, attachment and comments).
|
||||
|
||||
![][9]
|
||||
|
||||
Now you can make various different garden designs! This is one of the 6 designs that I created for my own garden.
|
||||
|
||||
![][10]
|
||||
|
||||
The last feature that I like to mention is the export possibilities. There is a lot of export options here, including Jpeg, Tiff, PDF, PS, EPS, Word, PowerPoint, Excel, HTML, SVG and Visio. In the unlicensed version, all exports work except for the Visio export. In the PDF you will see a watermark “Created by Unlicensed Version”.
|
||||
|
||||
![][11]
|
||||
|
||||
### Conclusion
|
||||
|
||||
As this is proprietary software, you will have to pay for it after 14 days. Unfortunately, the price is quite high. As a Linux user, you can only select the [Lifetime license][12], which currently costs $ 245. It is a very complete package (280 different types of diagrams), but I find the pricing too high for my purposes. And there is no option to pay less. For professional users I can imagine that this price would not be a big issue, as the software will pay itself back when you get payed for making designs. For me personally, it was a very nice experience to use this limited trial and it helped me to think of different ways in which I can redesign my garden.
|
||||
|
||||
**Published on: 16 august 2018**
|
||||
|
||||
### A FOSS alternative found!
|
||||
|
||||
Thanks to reddit user compairelapin, I have found an open source alternative. It is called Sweet Home 3D and its available in the [openSUSE package search][13]. In a future post, I will take a look at this software and compare it to Edraw Max.
|
||||
|
||||
**Updated on: 17 august 2018**
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.fossadventures.com/designing-your-garden-with-edraw-max/
|
||||
|
||||
作者：[Martin De Boer][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.fossadventures.com/author/martin_de_boer/
|
||||
[1]:https://www.bbc.co.uk/programmes/b006mw1h
|
||||
[2]:https://software.opensuse.org/
|
||||
[3]:https://www.edrawsoft.com/edraw-max.php
|
||||
[4]:https://www.edrawsoft.com/download-edrawmax.php
|
||||
[5]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-01-1024x463.jpeg
|
||||
[6]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-03.jpeg
|
||||
[7]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-04.jpeg
|
||||
[8]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-05.jpeg
|
||||
[9]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-06.jpeg
|
||||
[10]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-07.jpeg
|
||||
[11]:https://www.fossadventures.com/wp-content/uploads/2018/08/Edraw-Max-08.jpeg
|
||||
[12]:https://www.edrawsoft.com/orderedrawmax.php
|
||||
[13]:https://software.opensuse.org/package/SweetHome3D
|
||||
@ -0,0 +1,224 @@
|
||||
AryaLinux: A Distribution and a Platform
|
||||
======
|
||||
|
||||
|
||||
|
||||
Most Linux distributions are simply that: A distribution of Linux that offers a variation on an open source theme. You can download any of those distributions, install it, and use it. Simple. There’s very little mystery to using Linux these days, as the desktop is incredibly easy to use and server distributions are required in business.
|
||||
|
||||
But not every Linux distribution ends with that idea; some go one step further and create both a distribution and a platform. Such is the case with [AryaLinux][1]. What does that mean? Easy. AryaLinux doesn’t only offer an installable, open source operating system, they offer a platform with which users can build a complete GNU/Linux operating system. The provided scripts were created based on the instructions from [Linux From Scratch][2] and [Beyond Linux From Scratch][3].
|
||||
|
||||
If you’ve ever attempted to build you own Linux distribution, you probably know how challenging it can be. AryaLinux has made that process quite a bit less stressful. In fact, although the build can take quite a lot of time (up to 48 hours), the process of building the AryaLinux platform is quite easy.
|
||||
|
||||
But don’t think that’s the only way you can have this distribution. You can download a live version of AryaLinux and install as easily as if you were working with Ubuntu, Linux Mint, or Elementary OS.
|
||||
|
||||
Let’s get AryaLinux up and running from the live distribution and then walk through the process of building the platform, using the special builder image.
|
||||
|
||||
### The Live distribution
|
||||
|
||||
From the [AryaLinux download pag][4]e, you can get a version of the operating system that includes either [GNOME][5] or [Xfce][6]. I chose the GNOME route and found it to be configured to include Dash to dock and Applications menu extensions. Both of these will please most average GNOME users. Once you’ve downloaded the ISO image, burn it to either a DVD/CD or to a USB flash drive and boot up the live instance. Do note, you need to have at least 25GB of space on a drive to install AryaLinux. If you’re planning on testing this out as a virtual machine, create a 30-40 GB virtual drive, otherwise the installer will fail every time.
|
||||
|
||||
Once booted, you will be presented with a login screen, with the default user selected. Simply click the user and login (there is no password required).
|
||||
|
||||
To locate the installer, click the Applications menu, click Activities Overview, type “installer” and click on the resulting entry. This will launch the AryaLinux installer … one that looks very familiar to many Linux installers (Figure 1).
|
||||
|
||||
![AryaLinux installer][8]
|
||||
|
||||
Figure 1: The AryaLinux installer is quite easy to navigate.
|
||||
|
||||
[Used with permission][9]
|
||||
|
||||
In the next window (Figure 2), you are required to define a root partition. To do this, type “/” (no quotes) in the Choose the root partition section.
|
||||
|
||||
![root partition][11]
|
||||
|
||||
Figure 2: Defining your root partition for the AryaLinux installation.
|
||||
|
||||
[Used with permission][9]
|
||||
|
||||
If you don’t define a home partition, it will be created for you. If you don’t define a swap partition, none will be created. If you have a need to create a home partition outside of the standard /home, do it here. The next installation windows have you do the following:
|
||||
|
||||
* Create a standard user.
|
||||
|
||||
* Create an administrative password.
|
||||
|
||||
* Choose locale and keyboard.
|
||||
|
||||
* Choose your timezone.
|
||||
|
||||
|
||||
|
||||
|
||||
That’s all there is to the installation. Once it completes, reboot, remove the media (or delete the .iso from your Virtual Machine storage listing), and boot into your newly-installed AryaLinux operating system.
|
||||
|
||||
### What’s there?
|
||||
|
||||
Out of the box, you should find everything necessary to use AryaLinux as a full-functioning desktop distribution. Included is:
|
||||
|
||||
* LibreOffice
|
||||
|
||||
* Rhythmbox
|
||||
|
||||
* Files
|
||||
|
||||
* GNOME Maps
|
||||
|
||||
* GIMP
|
||||
|
||||
* Simple Scan
|
||||
|
||||
* Chromium
|
||||
|
||||
* Transmission
|
||||
|
||||
* Avahi SSH/VNC Server Browser
|
||||
|
||||
* Qt5 Assistant/Designer/Linguist/QDbusViewer
|
||||
|
||||
* Brasero
|
||||
|
||||
* Cheese
|
||||
|
||||
* Echomixer
|
||||
|
||||
* VLC
|
||||
|
||||
* Network Tools
|
||||
|
||||
* GParted
|
||||
|
||||
* dconf Editor
|
||||
|
||||
* Disks
|
||||
|
||||
* Disk Usage Analyzer
|
||||
|
||||
* Document Viewer
|
||||
|
||||
* And more
|
||||
|
||||
|
||||
|
||||
|
||||
### The caveats
|
||||
|
||||
It should be noted that this is the first official release of AryaLinux, so there will be issues. Right off the bat I realized that no matter what I tried, I could not get the terminal to open. Unfortunately, the terminal is a necessary tool for this distribution, as there is no GUI for updating or installing packages. In order to get to a bash prompt, I had to use a virtual screen. That’s when the next caveat came into play. The package manager for AryaLinux is alps, but its primary purpose is working in conjunction with the build scripts to install the platform. Unfortunately there is no included man page for alps on AryaLinux and the documentation is very scarce. Fortunately, the developers did think to roll in Flatpak support, so if you’re a fan of Flatpak, you can install anything you need (so long as it’s available as a flatpak package) using that system.
|
||||
|
||||
### Building the platform
|
||||
|
||||
Let’s talk about building the AryaLinux platform. This isn’t much harder than installing the standard distribution, only it’s done via the command line. Here’s what you do:
|
||||
|
||||
1. Download the [AryaLinux Builder Disk][12].
|
||||
|
||||
2. Burn the ISO to either DVD/CD or USB flash drive.
|
||||
|
||||
3. Boot the live image.
|
||||
|
||||
4. Once you reach the desktop, open a terminal window from the menu.
|
||||
|
||||
5. Change to the root user with the command sudo su.
|
||||
|
||||
6. Change directories with the command cd aryalinux/base-system
|
||||
|
||||
7. Run the build script with the command ./build-arya
|
||||
|
||||
|
||||
|
||||
|
||||
You will first be asked if you want to start a fresh build or resume a build (Figure 3). Remember, the AryaLinux build takes a LOT of time, so there might be an instance where you’ve started a build and need to resume.
|
||||
|
||||
![AryaLinux build][14]
|
||||
|
||||
Figure 3: Running the AryaLinux build script.
|
||||
|
||||
[Used with permission][9]
|
||||
|
||||
To start a new build, type “1” and then hit Enter on your keyboard. You will now be asked to define a number of options (in order to fulfill the build script requirements). Those options are:
|
||||
|
||||
* Bootloader Device
|
||||
|
||||
* Root Partition
|
||||
|
||||
* Home Partition
|
||||
|
||||
* Locale
|
||||
|
||||
* OS Name
|
||||
|
||||
* OS Version
|
||||
|
||||
* OS Codename
|
||||
|
||||
* Domain Name
|
||||
|
||||
* Keyboard Layout
|
||||
|
||||
* Printer Paper Size
|
||||
|
||||
* Enter Full Name
|
||||
|
||||
* Username
|
||||
|
||||
* Computer Name
|
||||
|
||||
* Use multiple cores for build (y/n)
|
||||
|
||||
* Create backups (y/n)
|
||||
|
||||
* Install X Server (y/n)
|
||||
|
||||
* Install Desktop Environment (y/n)
|
||||
|
||||
* Choose Desktop Environment (XFCE, Mate, KDE, GNOME)
|
||||
|
||||
* Do you want to configure advanced options (y/n)
|
||||
|
||||
* Create admin password
|
||||
|
||||
* Create password for standard user
|
||||
|
||||
* Install bootloader (y/n)
|
||||
|
||||
* Create Live ISO (y/n)
|
||||
|
||||
* Select a timezone
|
||||
|
||||
|
||||
|
||||
|
||||
After you’ve completed the above, the build will start. Don’t bother watching it, as it will take a very long time to complete (depending upon your system and network connection). In fact, the build can take anywhere from 8-48 hours. After the build completes, reboot and log into your newly built AryaLinux platform.
|
||||
|
||||
### Who is AryaLinux for?
|
||||
|
||||
I’ll be honest, if you’re just a standard desktop user, AryaLinux is not for you. Although you can certainly get right to work on the desktop, if you need anything outside of the default applications, you might find it a bit too much trouble to bother with. If, on the other hand, you’re a developer, AryaLinux might be a great platform for you. Or, if you just want to see what it’s like to build a Linux distribution from scratch, AryaLinux is a pretty easy route.
|
||||
|
||||
Even with its quirks, AryaLinux holds a lot of promise as both a Linux distribution and platform. If the developers can see to it to build a GUI front-end for the alps package manager, AryaLinux could make some serious noise.
|
||||
|
||||
Learn more about Linux through the free ["Introduction to Linux" ][15]course from The Linux Foundation and edX.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/learn/intro-to-linux/2018/8/aryalinux-distribution-and-platform
|
||||
|
||||
作者：[Jack Wallen][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://www.linux.com/users/jlwallen
|
||||
[1]:http://aryalinux.org
|
||||
[2]:http://www.linuxfromscratch.org/
|
||||
[3]:http://www.linuxfromscratch.org/blfs/
|
||||
[4]:http://aryalinux.org/downloads/
|
||||
[5]:https://sourceforge.net/projects/aryalinux/files/releases/1.0/aryalinux-gnome-1.0-x86_64-fixed.iso
|
||||
[6]:https://sourceforge.net/projects/aryalinux/files/releases/1.0/aryalinux-xfce-1.0-x86_64.iso
|
||||
[7]:/files/images/aryalinux1jpg
|
||||
[8]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/aryalinux_1.jpg?itok=vR11z5So (AryaLinux installer)
|
||||
[9]:/licenses/category/used-permission
|
||||
[10]:/files/images/aryalinux2jpg
|
||||
[11]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/aryalinux_2.jpg?itok=Lm50af-y (root partition)
|
||||
[12]:https://sourceforge.net/projects/aryalinux/files/releases/1.0/aryalinux-builder-1.0-x86_64.iso
|
||||
[13]:/files/images/aryalinux3jpg
|
||||
[14]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/aryalinux_3.jpg?itok=J-GUq99C (AryaLinux build)
|
||||
[15]:https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux
|
||||
@ -0,0 +1,282 @@
|
||||
Cloudgizer: An introduction to a new open source web development tool
|
||||
======
|
||||
|
||||
|
||||
|
||||
[Cloudgizer][1] is a free open source tool for building web applications. It combines the ease of scripting languages with the performance of [C][2], helping manage the development effort and run-time resources for cloud applications.
|
||||
|
||||
Cloudgizer works on [Red Hat][3]/[CentOS][4] Linux with the [Apache web server][5] and [MariaDB database][6]. It is licensed under [Apache License version 2][7].
|
||||
|
||||
### Hello World
|
||||
|
||||
In this example, we output an [HTTP][8] header and Hello World, followed by a horizontal line:
|
||||
```
|
||||
#include "cld.h"
|
||||
|
||||
void home()
|
||||
{
|
||||
/*<
|
||||
output-http-header
|
||||
|
||||
Hello World!
|
||||
<hr/>
|
||||
>*/
|
||||
}
|
||||
```
|
||||
|
||||
Cloudgizer code is written as a C comment with `/*<` and `>*/` at the beginning and ending, respectively.
|
||||
|
||||
Writing output to the web client is as simple as directly writing [HTML][9] code in your source. There are no API calls or special markups for that—simplicity is good because HTML (or [JavaScript][10], [CSS][11], etc.) will probably comprise a good chunk of your code.
|
||||
|
||||
### How it works
|
||||
|
||||
Cloudgizer source files (with a `.v` extension) are translated into C code by the `cld` command-line tool. C code is then compiled and linked with the web server and your application is ready to be used. For instance, generated code for the source file named `home.v` would be `__home.c`, if you'd like to examine it.
|
||||
|
||||
Much of your code will be written as "markups," small snippets of intuitive and descriptive code that let you easily do things like the following:
|
||||
|
||||
* database queries
|
||||
* web programming
|
||||
* encoding and encryption
|
||||
* executing programs
|
||||
* safe string manipulation
|
||||
* file operations
|
||||
* sending emails
|
||||
|
||||
|
||||
|
||||
and other common tasks. For less common tasks, there is an API that covers broader functionality. And ultimately, you can write any C code and use any libraries you wish to complete your task.
|
||||
|
||||
The `main()` function is generated by Cloudgizer and is a part of the framework, which provides Apache and database integration and other services. One such service is tracing and debugging (including memory garbage collection, underwrite/overwrite detection, run-time HTML linting, etc.). A program crash produces a full stack, including the source code lines, and the crash report is emailed to you the moment it happens.
|
||||
|
||||
A Cloudgizer application is linked with the Apache server as an Apache module in a pre-fork configuration. This means the Apache web server will pre-fork a number of processes and direct incoming requests to them. The Apache module mechanism provides high-performance request handling for applications.
|
||||
|
||||
All Cloudgizer applications run under the same Linux user, with each application separated under its own application directory. This user is also the Apache user; i.e., the user running the web server.
|
||||
|
||||
Each application has its own database with the name matching that of the application. Cloudgizer establishes and maintains database connections across requests, increasing performance.
|
||||
|
||||
### Development process
|
||||
|
||||
The process of compiling your source code and building an installation file is automated. By using the `cldpackapp` script, you’ll transform your code into pure C code and create an installation file (a [.tar.gz file][12]). The end user will install this file with the help of a configuration file called `appinfo`, producing a working web application. This process is straightforward:
|
||||
|
||||
|
||||
|
||||
The deployment process is designed to be automated if needed, with configurable parameters.
|
||||
|
||||
### Getting started
|
||||
|
||||
The development starts with installing [the Example application][13]. This sets up the development environment; you start with a Hello World and build up your application from there.
|
||||
|
||||
The Example application also serves as a smoke test because it has a number of code snippets that test various Cloudgizer features. It also gives you a good amount of example code (hence the name).
|
||||
|
||||
There are two files to be aware of as you start:
|
||||
|
||||
* `cld_handle_request.v` is where incoming requests (such as `GET`, `POST`, or a command-line execution) are processed.
|
||||
* `sourcelist` lists all your source code so that Cloudgizer can make your application.
|
||||
|
||||
|
||||
|
||||
In addition to `cld_handle_request.v`, `oops.v` implements an error handler, and `file_too_large.v` implements a response to an upload that's too large. These are already implemented in the Example application, and you can keep them as they are or tweak them.
|
||||
|
||||
Use `cldbuild` to recompile source-file (`.v`) changes, and `cldpackapp` to create an installer file for testing or release delivery via `cldgoapp`:
|
||||
|
||||
|
||||
|
||||
Deployment via `cldgoapp` lets you install an application from scratch or update from one version to another.
|
||||
|
||||
### Example
|
||||
|
||||
Here's a stock-ticker application that updates and reports on ticker prices. It is included in the Example application.
|
||||
|
||||
#### The code
|
||||
|
||||
The request handler checks the URL query parameter page, and if it's `stock`, it calls `function stock()`:
|
||||
```
|
||||
#include "cld.h"
|
||||
|
||||
void cld_handle_request()
|
||||
{
|
||||
/*<
|
||||
input-param page
|
||||
|
||||
if-string page="stock"
|
||||
c stock ();
|
||||
else
|
||||
report-error "Unrecognized page %s", page
|
||||
end-if
|
||||
>*/
|
||||
}
|
||||
```
|
||||
|
||||
The implementation of function `stock()` would be in file `stock.v`. The code adds a stock ticker if the URL query parameter action is `add` or shows all stock tickers if it is `show`.
|
||||
```
|
||||
#include "cld.h"
|
||||
|
||||
void stock()
|
||||
{
|
||||
/*<
|
||||
|
||||
output-http-header
|
||||
|
||||
<html>
|
||||
<body>
|
||||
input-param action
|
||||
|
||||
if-string action="add"
|
||||
input-param stock_name
|
||||
input-param stock_price
|
||||
|
||||
run-query#add_data = "insert into stock \
|
||||
(stock_name, stock_price) values \
|
||||
(<?stock_name?>, <?stock_price?>) \
|
||||
on duplicate key update \
|
||||
stock_price=<?stock_price?>"
|
||||
|
||||
query-result#add_data, error as \
|
||||
define err
|
||||
|
||||
if atoi(err) != 0
|
||||
report-error "Cannot update \
|
||||
stock price, error [%s]",err
|
||||
end-if
|
||||
end-query
|
||||
|
||||
<div>
|
||||
Stock price updated!
|
||||
</div>
|
||||
else-if-string action="show"
|
||||
<table>
|
||||
<tr>
|
||||
<td>Stock name</td>
|
||||
<td>Stock price</td>
|
||||
</tr>
|
||||
run-query#show_data = "select stock_name, \
|
||||
stock_price from stock"
|
||||
|
||||
<tr>
|
||||
<td>
|
||||
query-result#show_data, stock_name
|
||||
</td>
|
||||
<td>
|
||||
query-result#show_data, stock_price
|
||||
</td>
|
||||
</tr>
|
||||
end-query
|
||||
</table>
|
||||
else
|
||||
<div>Unrecognized request!</div>
|
||||
end-if
|
||||
</body>
|
||||
</html>
|
||||
>*/
|
||||
}
|
||||
```
|
||||
|
||||
#### The database table
|
||||
|
||||
The SQL table used would be:
|
||||
```
|
||||
create table stock (stock_name varchar(100) primary key, stock_price bigint);
|
||||
```
|
||||
|
||||
#### Making and packaging
|
||||
|
||||
To include `stock.v` in your Cloudgizer application, simply add it to the sourcelist file:
|
||||
```
|
||||
SOURCE_FILES=stock.v ....
|
||||
...
|
||||
stock.o : stock.v $(CLDINCLUDE)/cld.h $(HEADER_FILES)
|
||||
...
|
||||
```
|
||||
|
||||
To recompile changes to your code, use:
|
||||
```
|
||||
cldbuild
|
||||
```
|
||||
|
||||
To package your application for deployment, use:
|
||||
```
|
||||
cldpackapp
|
||||
```
|
||||
|
||||
When packaging an application, all additional objects you create (other than source code files), should be included in the `create.sh` file. This file sets up anything that the Cloudgizer application installer doesn't do; in this case, create the above SQL table. For example, the following code in your `create.sh` might suffice:
|
||||
```
|
||||
echo -e "drop table if exists stock;\ncreate table stock (stock_name varchar(100) primary key, stock_price bigint);" | mysql -u root -p$CLD_DB_ROOT_PWD -D $CLD_APP_NAME
|
||||
```
|
||||
|
||||
In `create.sh`, you can use any variables from the `appinfo` file (an installation configuration file). Those variables always include `CLD_DB_ROOT_PWD` (the root password database, which is always automatically cleared after installation for security), `CLD_APP_NAME` (the application and database name), `CLD_SERVER` (the URL of the installation server), `CLD_EMAIL` (the administration and notification email address), and others. You also have `CLD_APP_HOME_DIR` (the application's home directory) and `CLD_APP_INSTALL_DIR` (the location where the installation .tar.gz file had been unzipped so you can copy files from it). You can include any other variables in the `appinfo` file that you find useful.
|
||||
|
||||
#### Using the application
|
||||
|
||||
If your application name is 'myapp' running on myserver.com, then the URL to update a stock ticker would be this:
|
||||
```
|
||||
https://myserver.com/go.myapp?page=stock&action=add&stock_name=RHT&stock_price=500
|
||||
```
|
||||
|
||||
and the URL to show all stock tickers would be this:
|
||||
```
|
||||
https://myserver.com/go.myapp?page=stock&action=show
|
||||
```
|
||||
|
||||
(The URL path for all Cloudgizer applications always starts with `go.`; in this case, `go.myapp`.)
|
||||
|
||||
### Download and more examples
|
||||
|
||||
For more examples or download and installation details, visit [Zigguro.org/cloudgizer][14]. You'll also find the above example included in the installation (see [the Example application source code][15]).
|
||||
|
||||
For a much larger real-world example, check out the [source code][16] for [Rentomy][17], a free open source cloud application for rental property managers, written entirely in Cloudgizer and consisting of over 32,000 lines of code.
|
||||
|
||||
### Why use Cloudgizer?
|
||||
|
||||
Here's why Rentomy is written in Cloudgizer:
|
||||
|
||||
Originally, the goal was to use one of the popular [scripting languages][18] or [process virtual machines][19] like [Java][20], and to host Rentomy as a [Software-as-a-Service][21] (Saas) free of charge.
|
||||
|
||||
Since there are nearly 50 million rental units in the US alone, a free service like this needs superior software performance.
|
||||
|
||||
So squeezing more power from CPUs and using less RAM became very important. And with [Moore's Law slowing down][22], the bloat of popular web languages is costing more computing resources—we're talking about process-virtual machines, interpreters, [p-code generators][23], etc.
|
||||
|
||||
Debugging can be a pain because more layers of abstraction exist between you and what's really going on. Not every library can be easily used, so some functional and interoperability limitations remain.
|
||||
|
||||
On the other hand, in terms of big performance and a small footprint, there is no match for C. Most libraries are written in C for the same reason, so virtually any library you need is available, and debugging is straightforward.
|
||||
|
||||
However, C has issues with memory and overall safety (overwrites, underwrites, garbage collection, etc.), usability (it is low-level), application packaging, etc. And equally important, much of the development cost lies in the ease of writing and debugging the code and in its accessibility to novices.
|
||||
|
||||
From this perspective, Cloudgizer was born. Greater performance and a smaller footprint mean cheaper computing power. Easy, stable coding brings Zen to the development process, as does the ability to manage it better.
|
||||
|
||||
In hindsight, using Cloudgizer to build Rentomy was like using a popular scripting language without the issues.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/cloudgizer-intro
|
||||
|
||||
作者：[Sergio Mijares][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/sergio-mijares
|
||||
[1]:https://zigguro.org/cloudgizer/
|
||||
[2]:https://en.wikipedia.org/wiki/C_%28programming_language%29
|
||||
[3]:https://www.redhat.com/en
|
||||
[4]:https://www.centos.org/
|
||||
[5]:http://httpd.apache.org/
|
||||
[6]:https://mariadb.com/
|
||||
[7]:http://www.apache.org/licenses/LICENSE-2.0
|
||||
[8]:https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol
|
||||
[9]:https://en.wikipedia.org/wiki/HTML
|
||||
[10]:https://en.wikipedia.org/wiki/JavaScript
|
||||
[11]:https://en.wikipedia.org/wiki/Cascading_Style_Sheets
|
||||
[12]:https://opensource.com/article/17/7/how-unzip-targz-file
|
||||
[13]:https://zigguro.org/cloudgizer/#install
|
||||
[14]:https://zigguro.org/cloudgizer
|
||||
[15]:https://bitbucket.org/zigguro/cloudgizer_example/src
|
||||
[16]:https://bitbucket.org/zigguro/rentomy/src
|
||||
[17]:https://zigguro.org/rentomy/
|
||||
[18]:https://en.wikipedia.org/wiki/Scripting_language
|
||||
[19]:https://en.wikipedia.org/wiki/Virtual_machine
|
||||
[20]:https://www.java.com/en/
|
||||
[21]:https://en.wikipedia.org/wiki/Software_as_a_service
|
||||
[22]:https://www.engineering.com/ElectronicsDesign/ElectronicsDesignArticles/ArticleID/17209/DARPAs-100-Million-Programs-for-a-Silicon-Compiler-and-a-New-Open-Hardware-Ecosystem.aspx
|
||||
[23]:https://en.wikipedia.org/wiki/P-code_machine
|
||||
@ -0,0 +1,279 @@
|
||||
Linux DNS 查询剖析 – 第一部分
|
||||
============================================================
|
||||
|
||||
我经常与虚拟机集群打交道（[文1][3], [文2][4], [文3][5], [文4][6], [文5][7], [文6][8]），期间花费了大量时间试图掌握 [DNS 查询][9]的工作原理。遇到问题时，我有时只是不求甚解的使用 StackOverflow 上的“解决方案”；甚至那些“解决方案”有时并不工作。
|
||||
|
||||
最终我决定改变这种情况，决定一并找出所有问题的原因。我没有在网上找到完整手册或类似的其它东西，我问过一些同事，他们也是如此。
|
||||
|
||||
既然如此，我开始自己写这样的手册。
|
||||
|
||||
_如果你在找第二部分, 点击 [这里][1]_
|
||||
|
||||
结果发现，“Linux 执行一次 DNS 查询”的背后有相当多的工作。
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_“究竟有多难呢？”_
|
||||
|
||||
* * *
|
||||
|
||||
本系列文章试图将 Linux 主机上程序获取（域名对应的） IP 地址的过程及期间涉及的组件进行分块剖析。如果不理解这些块的协同工作方式，调试并解决 `dnsmasq`，`vagrant landrush` 和 `resolvconf` 等相关的问题会让人感到眼花缭乱。
|
||||
|
||||
同时这也是一份有价值的说明，指出原本很简单的东西可以如何随着时间的推移变得相当复杂。在弄清楚 DNS 查询的原理的过程中，我了解了大量不同的技术及其发展历程。
|
||||
|
||||
我甚至编写了一些[自动化脚本][10]，可以让我在虚拟机中进行实验。欢迎读者参与贡献或勘误。
|
||||
|
||||
请注意，本系列主题并不是“DNS 工作原理”，而是与查询 Linux 主机配置的真实 DNS 服务器（这里假设查询了 DNS 服务器，但后面你会看到有时并不需要查询）相关的内容，以及如何确定使用哪个查询结果，或者何时使用其它方式确定 IP 地址。
|
||||
|
||||
* * *
|
||||
|
||||
### 1) 其实并没有名为“DNS 查询”的系统调用
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_工作方式并非如此_
|
||||
|
||||
* * *
|
||||
|
||||
首先要了解的一点是，Linux 上并没有一个单独的方法可以完成 DNS 查询工作；至少没有如此<ruby>明确接口<rt>clean interface</rt></ruby>的核心<ruby>系统调用<rt>system call</rt></ruby>。
|
||||
|
||||
有一个标准 C 库函数调用 `[getaddrinfo][2]`，不少程序使用了该调用；但不是所有程序或应用都使用该调用！
|
||||
|
||||
我们只考虑两个简单的标准程序：`ping` 和 `host`：
|
||||
|
||||
```
|
||||
root@linuxdns1:~# ping -c1 bbc.co.uk | head -1
|
||||
PING bbc.co.uk (151.101.192.81) 56(84) bytes of data.
|
||||
```
|
||||
|
||||
```
|
||||
root@linuxdns1:~# host bbc.co.uk | head -1
|
||||
bbc.co.uk has address 151.101.192.81
|
||||
```
|
||||
|
||||
对于同一个域名，两个程序得到的 IP 地址是相同的；那么它们是使用同样的方法得到结果的吧？
|
||||
|
||||
事实并非如此。
|
||||
|
||||
下面文件给出了我主机上 `ping` 对应的 DNS 相关的系统调用：
|
||||
|
||||
```
|
||||
root@linuxdns1:~# strace -e trace=open -f ping -c1 google.com
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/lib/x86_64-linux-gnu/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
|
||||
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libnss_files.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/host.conf", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libnss_dns.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
open("/lib/x86_64-linux-gnu/libresolv.so.2", O_RDONLY|O_CLOEXEC) = 4
|
||||
PING google.com (216.58.204.46) 56(84) bytes of data.
|
||||
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 4
|
||||
64 bytes from lhr25s12-in-f14.1e100.net (216.58.204.46): icmp_seq=1 ttl=63 time=13.0 ms
|
||||
[...]
|
||||
```
|
||||
|
||||
下面是 `host` 对应的系统调用:
|
||||
|
||||
```
|
||||
$ strace -e trace=open -f host google.com
|
||||
[...]
|
||||
[pid 9869] open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/share/locale/en/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/share/locale/en/LC_MESSAGES/libdst.cat", O_RDONLY) = -1 ENOENT (No such file or directory)
|
||||
[pid 9869] open("/usr/lib/ssl/openssl.cnf", O_RDONLY) = 6
|
||||
[pid 9869] open("/usr/lib/x86_64-linux-gnu/openssl-1.0.0/engines/libgost.so", O_RDONLY|O_CLOEXEC) = 6[pid 9869] open("/etc/resolv.conf", O_RDONLY) = 6
|
||||
google.com has address 216.58.204.46
|
||||
[...]
|
||||
```
|
||||
|
||||
可以看出 `ping` 打开了 `nsswitch.conf` 文件，但 `host` 没有；但两个程序都打开了 `/etc/resolv.conf` 文件。
|
||||
|
||||
下面我们依次查看这两个 `.conf` 扩展名的文件。
|
||||
|
||||
* * *
|
||||
|
||||
### 2) NSSwitch 与 `/etc/nsswitch.conf`
|
||||
|
||||
我们已经确认应用可以自主决定选用哪个 DNS 服务器。很多应用（例如 `ping`）通过配置文件 `/etc/nsswitch.conf` （根据具体实现 (*)）参考 NSSwitch 完成选择。
|
||||
|
||||
###### (*) ping 实现的变种之多令人惊叹。我 _不_ 希望在这里讨论过多。
|
||||
|
||||
NSSwitch 不仅用于 DNS 查询，例如，还用于密码与用户信息查询。
|
||||
|
||||
NSSwitch 最初是 Solaris OS 的一部分，可以让应用无需将查询所需的文件或服务硬编码，而是在其它集中式的、无需应用开发人员管理的配置文件中找到。
|
||||
|
||||
下面是我的 `nsswitch.conf`：
|
||||
|
||||
```
|
||||
passwd: compat
|
||||
group: compat
|
||||
shadow: compat
|
||||
gshadow: files
|
||||
hosts: files dns myhostname
|
||||
networks: files
|
||||
protocols: db files
|
||||
services: db files
|
||||
ethers: db files
|
||||
rpc: db files
|
||||
netgroup: nis
|
||||
```
|
||||
|
||||
我们需要关注的是 `hosts` 行。我们知道 `ping` 用到 `nsswitch.conf` 文件，那么我们修改这个文件（的 `hosts` 行），看看能够如何影响 `ping`。
|
||||
|
||||
|
||||
* ### 修改 `nsswitch.conf`， `hosts` 行仅保留 `files`
|
||||
|
||||
如果你修改 `nsswitch.conf`，将 `hosts` 行仅保留 `files`：
|
||||
|
||||
`hosts: files`
|
||||
|
||||
此时， `ping` 无法获取 google.com 对应的 IP 地址：
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
ping: unknown host google.com
|
||||
```
|
||||
|
||||
但 `localhost` 的解析不受影响：
|
||||
|
||||
```
|
||||
$ ping -c1 localhost
|
||||
PING localhost (127.0.0.1) 56(84) bytes of data.
|
||||
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.039 ms
|
||||
```
|
||||
|
||||
此外，`host` 命令正常返回：
|
||||
|
||||
```
|
||||
$ host google.com
|
||||
google.com has address 216.58.206.110
|
||||
```
|
||||
|
||||
毕竟如我们之前看到的那样，`host` 不受 `nsswitch.conf` 影响。
|
||||
|
||||
* ### 修改 `nsswitch.conf`， `hosts` 行仅保留 `dns`
|
||||
|
||||
如果你修改 `nsswitch.conf`，将 `hosts` 行仅保留 `dns`：
|
||||
|
||||
`hosts: dns`
|
||||
|
||||
此时，google.com 的解析恢复正常：
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
PING google.com (216.58.198.174) 56(84) bytes of data.
|
||||
64 bytes from lhr25s10-in-f174.1e100.net (216.58.198.174): icmp_seq=1 ttl=63 time=8.01 ms
|
||||
```
|
||||
|
||||
但 `localhost` 无法解析：
|
||||
|
||||
```
|
||||
$ ping -c1 localhost
|
||||
ping: unknown host localhost
|
||||
```
|
||||
|
||||
下图给出默认 NSSwitch 中 `hosts` 行对应的查询逻辑：
|
||||
|
||||
* * *
|
||||
|
||||
|
||||
|
||||
_我的 `hosts:` 配置是 `nsswitch.conf` 给出的默认值_
|
||||
|
||||
* * *
|
||||
|
||||
### 3) `/etc/resolv.conf`
|
||||
|
||||
我们已经知道 `host` 和 `ping` 都使用 `/etc/resolv.conf` 文件。
|
||||
|
||||
下面给出我主机的 `/etc/resolv.conf` 文件内容：
|
||||
|
||||
```
|
||||
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
|
||||
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
|
||||
nameserver 10.0.2.3
|
||||
```
|
||||
|
||||
先忽略前两行，后面我们会回过头来看这部分（它们很重要，但你还需要一些知识储备）。
|
||||
|
||||
其中 `nameserver` 行指定了查询用到的 DNS 服务器。
|
||||
|
||||
如果将该行注释掉：
|
||||
|
||||
```
|
||||
#nameserver 10.0.2.3
|
||||
```
|
||||
|
||||
再次运行：
|
||||
|
||||
```
|
||||
$ ping -c1 google.com
|
||||
ping: unknown host google.com
|
||||
```
|
||||
|
||||
解析失败了，这是因为没有可用的 nameserver (*)。
|
||||
|
||||
|
||||
###### * 另一个需要注意的地方： `host` 在没有指定 nameserver 的情况下会尝试 127.0.0.1:53。
|
||||
|
||||
该文件中还可以使用其它选项。例如，你可以在 `resolv.conf` 文件中增加如下行：
|
||||
|
||||
```
|
||||
search com
|
||||
```
|
||||
然后执行 `ping google` （不写 `.com`）
|
||||
|
||||
```
|
||||
$ ping google
|
||||
PING google.com (216.58.204.14) 56(84) bytes of data.
|
||||
```
|
||||
|
||||
程序会自动为你尝试 `.com` 域。
|
||||
|
||||
### 第一部分总结
|
||||
|
||||
第一部分到此结束，下一部分我们会了解 `resolv.conf` 文件是如何创建和更新的。
|
||||
|
||||
下面总结第一部分涵盖的内容：
|
||||
|
||||
* 操作系统中并不存在“DNS 查询”这个系统调用
|
||||
* 不同程序可能采用不同的策略获取名字对应的 IP 地址
|
||||
* 例如, `ping` 使用 `nsswitch`，后者进而使用（或可以使用） `/etc/hosts`，`/etc/resolv.conf` 以及主机名得到解析结果
|
||||
|
||||
* `/etc/resolv.conf` 用于决定：
|
||||
* 查询什么地址（LCTT 译注：这里可能指 search 带来的影响）
|
||||
* 使用什么 DNS 服务器执行查询
|
||||
|
||||
如果你曾认为 DNS 查询很复杂，请跟随这个系列学习吧。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://zwischenzugs.com/2018/06/08/anatomy-of-a-linux-dns-lookup-part-i/
|
||||
|
||||
作者：[dmatech][a]
|
||||
译者：[pinewall](https://github.com/pinewall)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://twitter.com/dmatech2
|
||||
[1]:https://zwischenzugs.com/2018/06/18/anatomy-of-a-linux-dns-lookup-part-ii/
|
||||
[2]:http://man7.org/linux/man-pages/man3/getaddrinfo.3.html
|
||||
[3]:https://zwischenzugs.com/2017/10/31/a-complete-chef-infrastructure-on-your-laptop/
|
||||
[4]:https://zwischenzugs.com/2017/03/04/a-complete-openshift-cluster-on-vagrant-step-by-step/
|
||||
[5]:https://zwischenzugs.com/2017/03/04/migrating-an-openshift-etcd-cluster/
|
||||
[6]:https://zwischenzugs.com/2017/03/04/1-minute-multi-node-vm-setup/
|
||||
[7]:https://zwischenzugs.com/2017/03/18/clustered-vm-testing-how-to/
|
||||
[8]:https://zwischenzugs.com/2017/10/27/ten-things-i-wish-id-known-before-using-vagrant/
|
||||
[9]:https://zwischenzugs.com/2017/10/21/openshift-3-6-dns-in-pictures/
|
||||
[10]:https://github.com/ianmiell/shutit-linux-dns/blob/master/linux_dns.py
|
||||
@ -1,15 +1,15 @@
|
||||
Slices from the ground up
|
||||
============================================================
|
||||
从零开始学习切片
|
||||
======
|
||||
|
||||
这篇文章最初的灵感来源于我与一个使用切片作栈的同事的一次聊天。那次聊天，话题最后拓展到了 Go 语言中的切片是如何工作的。我认为把这些知识记录下来会帮到别人。
|
||||
这篇文章受到了我与同事讨论使用<ruby>切片<rt>slice</rt></ruby>作为<ruby>栈<rt>stack</rt></ruby>的一次聊天的启发。后来话题聊到了 Go 语言中的切片是如何工作的。我认为这些信息对别人也有用，所以就把它记录了下来。
|
||||
|
||||
### 数组
|
||||
|
||||
任何关于 Go 语言的切片的讨论都要从另一个数据结构，也就是 Go 语言的数组开始。Go 语言的数组有两个特性：
|
||||
任何关于 Go 语言切片的讨论都要从另一个数据结构也就是<ruby>数组<rt>array</rt></ruby>开始。Go 的数组有两个特性：
|
||||
|
||||
1. 数组的长度是固定的；`[5]int` 是由 5 个 `unt` 构成的数组，和`[3]int` 不同。
|
||||
1. 数组的长度是固定的；`[5]int` 是由 5 个 `int` 构成的数组，和 `[3]int` 不同。
|
||||
2. 数组是值类型。看下面这个示例：
|
||||
|
||||
2. 数组是值类型。考虑如下示例：
|
||||
```
|
||||
package main
|
||||
|
||||
@ -23,19 +23,19 @@ Slices from the ground up
|
||||
}
|
||||
```
|
||||
|
||||
语句 `b := a` 定义了一个新的变量 `b`，类型是 `[5]int`，然后把 `a` 中的内容_复制_到 `b` 中。改变 `b` 中的值对 `a` 中的内容没有影响，因为 `a` 和 `b` 是相互独立的值。 [1][1]
|
||||
语句 `b := a` 定义了一个类型是 `[5]int` 的新变量 `b`，然后把 `a` 中的内容 _复制_ 到 `b` 中。改变 `b` 对 `a` 中的内容没有影响，因为 `a` 和 `b` 是相互独立的值。[^1]
|
||||
|
||||
### 切片
|
||||
|
||||
Go 语言的切片和数组的主要有如下两个区别：
|
||||
|
||||
1. 切片没有一个固定的长度。切片的长度不是它类型定义的一部分，而是由切片内部自己维护的。我们可以使用内置的 `len` 函数知道他的长度。
|
||||
1. 切片没有一个固定的长度。切片的长度不是它类型定义的一部分，而是由切片内部自己维护的。我们可以使用内置的 `len` 函数知道它的长度。[^2]
|
||||
2. 将一个切片赋值给另一个切片时 _不会_ 对切片进行复制操作。这是因为切片没有直接保存它的内部数据，而是保留了一个指向 _底层数组_ [^3] 的指针。数据都保留在底层数组里。
|
||||
|
||||
2. 将一个切片赋值给另一个切片时 _不会_ 将切片进行复制操作。这是因为切片没有直接保存它的内部数据，而是保留了一个指向 _底层数组_ [3][3]的指针。数据都保留在底层数组里。
|
||||
|
||||
基于第二个特性，两个切片可以享有共同的底层数组。考虑如下示例：
|
||||
基于第二个特性，两个切片可以享有共同的底层数组。看下面的示例：
|
||||
|
||||
1. 对切片取切片
|
||||
|
||||
```
|
||||
package main
|
||||
|
||||
@ -49,9 +49,10 @@ Go 语言的切片和数组的主要有如下两个区别：
|
||||
}
|
||||
```
|
||||
|
||||
在这个例子里，`a` 和 `b` 享有共同的底层数组 —— 尽管 `b` 的起始值在数组里的偏移不同，两者的长度也不同。通过 `b` 修改底层数组的值也会导致 `a` 里的值的改变。
|
||||
在这个例子里，`a` 和 `b` 享有共同的底层数组 —— 尽管 `b` 在数组里的起始偏移量不同，两者的长度也不同。通过 `b` 修改底层数组的值也会导致 `a` 里的值的改变。
|
||||
|
||||
2. 将切片传进函数
|
||||
|
||||
```
|
||||
package main
|
||||
|
||||
@ -72,10 +73,10 @@ Go 语言的切片和数组的主要有如下两个区别：
|
||||
|
||||
在这个例子里，`a` 作为形参 `s` 的实参传进了 `negate` 函数，这个函数遍历 `s` 内的元素并改变其符号。尽管 `nagate` 没有返回值，且没有接触到 `main` 函数里的 `a`。但是当将之传进 `negate` 函数内时，`a` 里面的值却被改变了。
|
||||
|
||||
大多数程序员都能直观地了解 Go 语言切片的底层数组是如何工作的，因为它与其他语言中类似数组的工作方式类似。比如下面就是使用 Python 重写的这一小节的第一个示例：
|
||||
大多数程序员都能直观地了解 Go 语言切片的底层数组是如何工作的，因为它与其它语言中类似数组的工作方式类似。比如下面就是使用 Python 重写的这一小节的第一个示例：
|
||||
|
||||
```
|
||||
Python 2.7.10 (default, Feb 7 2017, 00:08:15)
|
||||
Python 2.7.10 (default, Feb 7 2017, 00:08:15)
|
||||
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.34)] on darwin
|
||||
Type "help", "copyright", "credits" or "license" for more information.
|
||||
>>> a = [1,2,3,4,5]
|
||||
@ -98,11 +99,11 @@ irb(main):004:0> a
|
||||
=> [1, 2, 0, 4, 5]
|
||||
```
|
||||
|
||||
在大多数将数组视为对象或者是引用类型的语言也是如此。[4][8]
|
||||
在大多数将数组视为对象或者是引用类型的语言也是如此。[^4]
|
||||
|
||||
### 切片头
|
||||
|
||||
让切片得以同时拥有值和指针的特性的魔法来源于切片实际上是一个结构体类型。这个结构体通常叫做 _切片头_，这里是 [反射包内的相关定义][20]。且片头的定义大致如下：
|
||||
切片同时拥有值和指针特性的神奇之处在于理解切片实际上是一个<ruby>结构体<rt>struct</rt></ruby>类型。这个结构体通常叫做 _切片头_，这里是[<ruby>反射<rt>reflect</rt></ruby>包内的相关定义][7]。切片头的定义大致如下：
|
||||
|
||||
|
||||
|
||||
@ -116,9 +117,9 @@ type slice struct {
|
||||
}
|
||||
```
|
||||
|
||||
这个头很重要，因为和[ `map` 以及 `chan` 这两个类型不同][21]，切片是值类型，当被赋值或者被作为函数的参数时候会被复制过去。
|
||||
这很重要，因为和 [`map` 以及 `chan` 这两个类型不同][7]，切片是值类型，当被赋值或者被作为参数传入函数时候会被复制过去。
|
||||
|
||||
程序员们都能理解 `square` 的形参 `v` 和 `main` 中声明的 `v` 的是相互独立的，我们一次为例。
|
||||
程序员们都能理解 `square` 的形参 `v` 和 `main` 中声明的 `v` 的是相互独立的。请看下面的例子：
|
||||
|
||||
```
|
||||
package main
|
||||
@ -136,7 +137,7 @@ func main() {
|
||||
}
|
||||
```
|
||||
|
||||
因此 `square` 对自己的形参 `v` 的操作没有影响到 `main` 中的 `v`。下面这个示例中的 `s` 也是 `main` 中声明的切片 `s` 的独立副本，_而不是_指向 `main` 的 `s` 的指针。
|
||||
因此 `square` 对自己的形参 `v` 的操作没有影响到 `main` 中的 `v`。下面这个示例中的 `s` 也是 `main` 中声明的切片 `s` 的独立副本， _而不是_ 指向 `main` 的 `s` 的指针。
|
||||
|
||||
```
|
||||
package main
|
||||
@ -154,13 +155,13 @@ func main() {
|
||||
}
|
||||
```
|
||||
|
||||
Go 语言的切片是作为值传递的这一点很是不寻常。当你在 Go 语言内定义一个结构体时，90% 的时间里传递的都是这个结构体的指针。[5][9] 切片的传递方式真的很不寻常，我能想到的唯一与之相同的例子只有 `time.Time`。
|
||||
Go 的切片是作为值传递的这一点很是不寻常。当你在 Go 内定义一个结构体时，90% 的时间里传递的都是这个结构体的指针[^5]。切片的传递方式真的很不寻常，我能想到的唯一与之相同的例子只有 `time.Time`。
|
||||
|
||||
切片作为值传递而不是作为指针传递这一点会让很多想要理解切片的工作原理的 Go 程序员感到困惑，这是可以理解的。你只需要记住，当你对切片进行赋值，取切片，传参或者作为返回值等操作时，你是在复制结构体内的三个位域：指针，长度，以及容量。
|
||||
切片作为值传递而不是作为指针传递这一特殊行为会让很多想要理解切片的工作原理的 Go 程序员感到困惑，这是可以理解的。你只需要记住，当你对切片进行赋值，取切片，传参或者作为返回值等操作时，你是在复制切片头结构的三个字段：指向底层数组的指针，长度，以及容量。
|
||||
|
||||
### 总结
|
||||
|
||||
我们来用我们引出这一话题的切片作为栈的例子来总结下本文的内容：
|
||||
我们来用引出这一话题的切片作为栈的例子来总结下本文的内容：
|
||||
|
||||
```
|
||||
package main
|
||||
@ -181,7 +182,7 @@ func main() {
|
||||
}
|
||||
```
|
||||
|
||||
在 `main` 函数的最开始我们把一个 `nil` 切片以及 `level` 0传给了函数 `f`。在函数 `f` 里我们把当前的 `level` 添加到切片的后面，之后增加 `level` 的值并进行递归。一旦 `level` 大于 5，函数返回，打印出当前的 `level` 以及他们复制到的 `s` 的内容。
|
||||
在 `main` 函数的最开始我们把一个 `nil` 切片以及 `level` 的值 0 传给了函数 `f`。在函数 `f` 里我们把当前的 `level` 添加到切片的后面，之后增加 `level` 的值并进行递归。一旦 `level` 大于 5，函数返回，打印出当前的 `level` 以及它们复制到的 `s` 的内容。
|
||||
|
||||
```
|
||||
level: 5 slice: [0 1 2 3 4 5]
|
||||
@ -192,69 +193,46 @@ level: 1 slice: [0 1]
|
||||
level: 0 slice: [0]
|
||||
```
|
||||
|
||||
你可以注意到在每一个 `level` 内 `s` 的值没有被别的 `f` 的调用影响，尽管当计算更高阶的 `level` 时作为 `append` 的副产品，调用栈内的四个 `f` 函数创建了四个底层数组，但是没有影响到当前各自的切片。
|
||||
你可以注意到在每一个 `level` 内 `s` 的值没有被别的 `f` 的调用影响，尽管当计算更高的 `level` 时作为 `append` 的副产品，调用栈内的四个 `f` 函数创建了四个底层数组[^6]，但是没有影响到当前各自的切片。
|
||||
|
||||
### 了解更多
|
||||
### 扩展阅读
|
||||
|
||||
如果你想要了解更多 Go 语言内切片运行的原理，我建议看看 Go 博客里的这些文章：
|
||||
|
||||
* [Go Slices: usage and internals][11] (blog.golang.org)
|
||||
|
||||
* [Arrays, slices (and strings): The mechanics of ‘append’][12] (blog.golang.org)
|
||||
* [Go Slices: usage and internals][5] (blog.golang.org)
|
||||
* [Arrays, slices (and strings): The mechanics of 'append'][6] (blog.golang.org)
|
||||
|
||||
### 注释
|
||||
|
||||
1. 这不是数组才有的特性，在 Go 语言里，_一切_ 赋值都是复制过去的，
|
||||
|
||||
2. 你可以在对数组使用 `len` 函数，但是得到的结果是多少人尽皆知。[][14]
|
||||
|
||||
3. 也叫做后台数组，以及更不严谨的说法是后台切片。[][15]
|
||||
|
||||
4. Go 语言里我们倾向于说值类型以及指针类型，因为 C++ 的引用会使使用引用类型这个词产生误会。但是在这里我说引用类型是没有问题的。[][16]
|
||||
|
||||
5. 如果你的结构体有[定义在其上的方法或者实现了什么接口][17],那么这个比率可以飙升到接近 100%。[][18]
|
||||
|
||||
6. 证明留做习题。
|
||||
[^1]: 这不是数组才有的特性，在 Go 语言里中 _一切_ 赋值都是复制过去的。
|
||||
[^2]: 你也可以在对数组使用 `len` 函数，但是得到的结果是多少人尽皆知。
|
||||
[^3]: 有时也叫做<ruby>后台数组<rt>backing array</rt></ruby>，以及更不严谨的说法是后台切片。
|
||||
[^4]: Go 语言里我们倾向于说值类型以及指针类型，因为 C++ 的<ruby>引用<rt>reference</rt></ruby>类型这个词产生误会。但在这里我认为调用数组作为引用类型是没有问题的。
|
||||
[^5]: 如果你的结构体有[定义在其上的方法或者用于满足某个接口][7]，那么你传入结构体指针的比率可以飙升到接近 100%。
|
||||
[^6]: 证明留做习题。
|
||||
|
||||
### 相关文章：
|
||||
|
||||
1. [If a map isn’t a reference variable, what is it?][4]
|
||||
1. [If a map isn't a reference variable, what is it?][1]
|
||||
2. [What is the zero value, and why is it useful?][2]
|
||||
3. [The empty struct][3]
|
||||
4. [Should methods be declared on T or *T][4]
|
||||
|
||||
2. [What is the zero value, and why is it useful ?][5]
|
||||
|
||||
3. [The empty struct][6]
|
||||
|
||||
4. [Should methods be declared on T or *T][7]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
---
|
||||
|
||||
via: https://dave.cheney.net/2018/07/12/slices-from-the-ground-up
|
||||
|
||||
作者：[Dave Cheney][a]
|
||||
译者：[name1e5s](https://github.com/name1e5s)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[pityonline](https://github.com/pityonline)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://dave.cheney.net/
|
||||
[1]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-1-3265
|
||||
[2]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-2-3265
|
||||
[3]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-3-3265
|
||||
[4]:https://dave.cheney.net/2017/04/30/if-a-map-isnt-a-reference-variable-what-is-it
|
||||
[5]:https://dave.cheney.net/2013/01/19/what-is-the-zero-value-and-why-is-it-useful
|
||||
[6]:https://dave.cheney.net/2014/03/25/the-empty-struct
|
||||
[7]:https://dave.cheney.net/2016/03/19/should-methods-be-declared-on-t-or-t
|
||||
[8]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-4-3265
|
||||
[9]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-5-3265
|
||||
[10]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-bottom-6-3265
|
||||
[11]:https://blog.golang.org/go-slices-usage-and-internals
|
||||
[12]:https://blog.golang.org/slices
|
||||
[13]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-1-3265
|
||||
[14]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-2-3265
|
||||
[15]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-3-3265
|
||||
[16]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-4-3265
|
||||
[17]:https://dave.cheney.net/2016/03/19/should-methods-be-declared-on-t-or-t
|
||||
[18]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-5-3265
|
||||
[19]:https://dave.cheney.net/2018/07/12/slices-from-the-ground-up#easy-footnote-6-3265
|
||||
[20]:https://golang.org/pkg/reflect/#SliceHeader
|
||||
[21]:https://dave.cheney.net/2017/04/30/if-a-map-isnt-a-reference-variable-what-is-it
|
||||
[a]: https://dave.cheney.net/
|
||||
[1]: https://dave.cheney.net/2017/04/30/if-a-map-isnt-a-reference-variable-what-is-it
|
||||
[2]: https://dave.cheney.net/2013/01/19/what-is-the-zero-value-and-why-is-it-useful
|
||||
[3]: https://dave.cheney.net/2014/03/25/the-empty-struct
|
||||
[4]: https://dave.cheney.net/2016/03/19/should-methods-be-declared-on-t-or-t
|
||||
[5]: https://blog.golang.org/go-slices-usage-and-internals
|
||||
[6]: https://blog.golang.org/slices
|
||||
[7]: https://golang.org/pkg/reflect/#SliceHeader
|
||||
|
||||
@ -1,634 +0,0 @@
|
||||
包管理器的进化
|
||||
======
|
||||
|
||||
|
||||
|
||||
今天，每个可计算设备都会使用某种软件来完成预定的任务。在软件开发的上古时期，为了找出软件中的“虫”和其他缺陷，软件会被严格的测试。在近十年间，人们希望通过持续不断的安装新版本的软件来解决软件的缺陷问题，软件被通过互联网来频繁分发，而不是在软件尚未发布前进行过多的测试。在很多情况下，每个独立的应用软件都有其自带的更新器。而其他一些软件则让用户自己去搞明白如何获取和升级软件。
|
||||
|
||||
Linux较早的采用了维护一个中心化的软件仓库来发布软件更新这种做法，用户可以在这个软件仓库里查找并安装软件。在这篇文章里， 笔者将回顾在Linux上的如何进行软件安装的崎岖历史，以及现代操作系统如何在软件安全漏洞不断被曝光中保持软件始终得到更新。
|
||||
|
||||
### 那么在包管理器出现之前在Linux上是如何安装软件的呢？
|
||||
曾几何时，软件都是通过FTP下载到本地或邮件列表（译注：即通过邮件列表发布源代码的补丁包）来分发的（最终这些发布方式在互联网的迅猛发展下都演化成为一个个现今常见的软件发布网站）。通常几个小补丁文件会被压缩成一个Tar格式的包，你需要做的是先解压这个包，然后仔细阅读当中的README文件， 如果你的系统上恰好有GCC（译注：GNU C Compiler）或者其他厂商的C编译器的话，你得首先运行./configure脚本，并在脚本后添加相应的参数如库函数的路径，创建可执行文件的路径等等，除此之外，configure脚本也会检查你操作系统上的软件依赖是否满足安装要求，如果configure正常执行完毕，一个Makefile文件将会被创建。
|
||||
|
||||
如果一个Makefile文件被成功创建， 你就可以接下去执行‘make’ 命令（这由你的编译器提供）。make命令也有很多参数，被称为make标识，这些标识能帮助优化最终生成出来的二进制可执行文件。在计算机世界的早期，这些优化是非常重要的，因为彼时的计算机硬件正在为了跟上软件迅速的发展而疲于奔命。今日今时，编译标识变得更加通用而不是为了优化哪些具体的硬件型号，这得益于现代硬件和现代软件相比已经变得成本低廉，唾手可得。
|
||||
|
||||
|
||||
最后，在make 完成之后， 你需要运行'make install'(或'sudo make install')(译注：依赖于你的用户权限) 来‘真正’将这个软件安装到你的系统上。可以想象，为你系统上的每一个软件都执行上述的流程将是多么无聊费时，更不用说如果更新一个已经安装的软件将会多复杂，多么需要精力投入。
|
||||
（译注：上述流程也称CMMI安装， 即Configure， Make， Make Install）
|
||||
### 那么软件包是什么？
|
||||
|
||||
’软件包‘（译注：下文简称包）这个概念是用来解决在软件安装升级过程中的复杂性的。包将软件安装升级中需要的多个数据文件合并成一个单独的文件，这将极大的提高可移植性和减小存储空间（译注：减少存储空间这一点在现在已经不再重要），包中的二进制可执行文件已经预先用安装开发者所选择的编译标识预编译。包本身包括了所有需要的元数据，如软件的名字，软件的说明，版本号，以及要运行这个软件所需要的依赖包等等。
|
||||
|
||||
各个不同的Linux发行版都创造了他们自己的包格式，其中做常用的包格式有：
|
||||
|
||||
* .deb: 这种包格式由Debian， Ubuntu， Linux Mint以及其他的变种使用。这是最早被发明的包类型。
|
||||
* .rpm: 这种包格式源自红帽子包管理器（译注： 取自英文的首字母）。使用这种包的Linux发行版有Red Hat, Fedora, SUSE以及其他一些较小的发行版。
|
||||
* .tar.xz: 这种包格式只是一个软件压缩包而已，Arch Linux使用这种发行版中立的格式来安装软件。
|
||||
|
||||
|
||||
尽管上述的包格式自身并不能管理软件的依赖问题，但是他们的出现将Linux软件包管理向前推进了一大步。
|
||||
|
||||
### 软件仓库到底是什么？
|
||||
|
||||
多年以前（当智能电话还没有像现在这样流行时），非Linux世界的用户是很难理解软件仓库的概念的。甚至今时今日，大多数完全工作在Windows下的用户还是习惯于打开浏览器，搜索要安装的软件（或升级包），下载然后安装。但是，智能电话传播了软件’商店’（译注： 对应Linux里的软件仓库）这样一个概念。智能电话用户获取软件和包管理器的工作方式已经非常相近了。些许不同的是，尽管大多数软件商店还在费力美化它的图形界面来吸引用户，大多数Linux用户还是愿意使用命令行来安装软件。总而言之，软件仓库是一个中心化的可安装软件列表，上面列举了在当前系统中预先配置好的软件仓库里所有可以安装的软件。下面我们举一些例子来说在各个不同的Linux发行版下如何在对应的软件仓库里搜寻某个特定的软件。
|
||||
|
||||
在Arch Linux下使用aurman
|
||||
|
||||
```
|
||||
user@arch ~ $ aurman -Ss kate
|
||||
|
||||
extra/kate 18.04.2-2 (kde-applications kdebase)
|
||||
Advanced Text Editor
|
||||
aur/kate-root 18.04.0-1 (11, 1.139399)
|
||||
Advanced Text Editor, patched to be able to run as root
|
||||
aur/kate-git r15288.15d26a7-1 (1, 1e-06)
|
||||
An advanced editor component which is used in numerous KDE applications requiring a text editing component
|
||||
```
|
||||
|
||||
在CentOS 7下使用 YUM
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum search kate
|
||||
|
||||
kate-devel.x86_64 : Development files for kate
|
||||
kate-libs.x86_64 : Runtime files for kate
|
||||
kate-part.x86_64 : Kate kpart plugin
|
||||
```
|
||||
|
||||
|
||||
在Ubuntu下使用APT
|
||||
|
||||
```
|
||||
user@ubuntu ~ $ apt search kate
|
||||
Sorting... Done
|
||||
Full Text Search... Done
|
||||
|
||||
kate/xenial 4:15.12.3-0ubuntu2 amd64
|
||||
powerful text editor
|
||||
|
||||
kate-data/xenial,xenial 4:4.14.3-0ubuntu4 all
|
||||
shared data files for Kate text editor
|
||||
|
||||
kate-dbg/xenial 4:15.12.3-0ubuntu2 amd64
|
||||
debugging symbols for Kate
|
||||
|
||||
kate5-data/xenial,xenial 4:15.12.3-0ubuntu2 all
|
||||
shared data files for Kate text editor
|
||||
```
|
||||
|
||||
### 最好用的包管理器有哪些？
|
||||
|
||||
如上示例的输出，包管理器用来和相应的软件仓库交互，获取软件的相应信息。下面对他们做一个简短介绍。
|
||||
|
||||
### 基于PRM包格式的包管理器
|
||||
|
||||
更新基于RPM的系统，特别是那些基于Red Hat技术的系统，有着非常有趣而又详细的历史。实际上，现在的[YUM][2]版本（企业级发布版）和[DNF][3]（社区版）就融合了好几个开源项目来提供他们现在的功能。
|
||||
|
||||
Red Hat最初使用的包管理器，即[RPM][4](红帽包管理器)，今时今日还在广泛使用着。不过，它的主要作用是安装本地的RPM包，而不是去在软件仓库搜索软件。一个叫'up2date'的包管理器被开发出来，它被用来通知用户包的最新更新，还能让用户在远程仓库里搜索软件并便捷的安装软件的依赖。尽管这个包管理器尽职尽责，一些社区成员还是感觉'up2date'有着明显的不足。
|
||||
|
||||
现在的YUM来自于好几个不同社区的努力。1999-2001年一群在Terra Soft Solution的伙计们开发了黄狗更新器（YUP），将其作为[Yellow Dog Linux][5]图形安装器的后端。杜克大学喜欢这个主意就决定去增强它的功能，他们开发了[黄狗更新器--修改版(YUM)][16]，这最终被用来帮助管理杜克大学的Red Hat系统。Yum壮大的很快，到2005年，它已经被超过一半的Linux市场所采用。今日，几乎所有的使用RPM的的Linux都会使用YUM来进行包管理（当然也有一些例外）。
|
||||
|
||||
### 使用YUM
|
||||
|
||||
为了能让YUM正常工作，比如从一个软件仓库里下载和安装包，仓库说明文件必须放在/etc/yum.repos.d/目录下且必须以'.repo'作为扩展名。如下是repo文件的内容：
|
||||
|
||||
```
|
||||
[local_base]
|
||||
name=Base CentOS (local)
|
||||
baseurl=http://7-repo.apps.home.local/yum-repo/7/
|
||||
enabled=1
|
||||
gpgcheck=0
|
||||
```
|
||||
|
||||
这是笔者本地仓库之一，这也是为什么gpgcheck值为零的原因。如果这个值为1的话，每个包都需要被秘钥签名，相应的秘钥也要导入到安装软件的系统上。因为这个软件仓库是笔者本人维护的且笔者信任这个仓库里的包，所以就不去对他们一一签名了。
|
||||
|
||||
|
||||
当一个仓库文件准备好时，你就能开始从远程软件仓库开始安装文件了。最基本的命令是'yum update',这将会更新所有已安装的包。你也不需要用特殊的命令来更新仓库本身，所有这一切都已自动完成了。运行命令示例如下：
|
||||
|
||||
```
|
||||
[user@centos ~]$ sudo yum update
|
||||
Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager
|
||||
local_base | 3.6 kB 00:00:00
|
||||
local_epel | 2.9 kB 00:00:00
|
||||
local_rpm_forge | 1.9 kB 00:00:00
|
||||
local_updates | 3.4 kB 00:00:00
|
||||
spideroak-one-stable | 2.9 kB 00:00:00
|
||||
zfs | 2.9 kB 00:00:00
|
||||
(1/6): local_base/group_gz | 166 kB 00:00:00
|
||||
(2/6): local_updates/primary_db | 2.7 MB 00:00:00
|
||||
(3/6): local_base/primary_db | 5.9 MB 00:00:00
|
||||
(4/6): spideroak-one-stable/primary_db | 12 kB 00:00:00
|
||||
(5/6): local_epel/primary_db | 6.3 MB 00:00:00
|
||||
(6/6): zfs/x86_64/primary_db | 78 kB 00:00:00
|
||||
local_rpm_forge/primary_db | 125 kB 00:00:00
|
||||
Determining fastest mirrors
|
||||
Resolving Dependencies
|
||||
--> Running transaction check
|
||||
```
|
||||
|
||||
如果你确定想让YUM在执行任何命令时不要停下来等待用户输入，你可以命令里放‘-y’标志，如'yum update -y'
|
||||
|
||||
|
||||
安装一个新包很简单。首先，用'yum search'搜索包的名字。
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum search kate
|
||||
|
||||
artwiz-aleczapka-kates-fonts.noarch : Kates font in Artwiz family
|
||||
ghc-highlighting-kate-devel.x86_64 : Haskell highlighting-kate library development files
|
||||
kate-devel.i686 : Development files for kate
|
||||
kate-devel.x86_64 : Development files for kate
|
||||
kate-libs.i686 : Runtime files for kate
|
||||
kate-libs.x86_64 : Runtime files for kate
|
||||
kate-part.i686 : Kate kpart plugin
|
||||
```
|
||||
|
||||
当你找到你要安装的包后，你可以用‘sudo yum install kate-devel -y’来安装。如果你安装了你不需要的软件，可以用‘sudo yum remove kdate-devel -y’来从系统上删除它，默认情况下，YUM会删除软件包以及它的依赖。
|
||||
|
||||
有些时候你甚至都不清楚要安装的包的名称，你只知道某个实用程序的名字。（译注：可以理解实用程序是安装包的子集）。例如，你想找实用程序‘updatedb‘(它是用来创建/更新由‘locate’命令创建的数据库的),直接试图安装'updatedb'会返回下面的结果：
|
||||
|
||||
```
|
||||
[user@centos ~]$ sudo yum install updatedb
|
||||
Loaded plugins: fastestmirror, langpacks
|
||||
Loading mirror speeds from cached hostfile
|
||||
No package updatedb available.
|
||||
Error: Nothing to do
|
||||
```
|
||||
|
||||
你可以搜索实用程序来自哪个包：
|
||||
|
||||
```
|
||||
[user@centos ~]$ yum whatprovides *updatedb
|
||||
Loaded plugins: fastestmirror, langpacks
|
||||
Loading mirror speeds from cached hostfile
|
||||
|
||||
bacula-director-5.2.13-23.1.el7.x86_64 : Bacula Director files
|
||||
Repo : local_base
|
||||
Matched from:
|
||||
Filename : /usr/share/doc/bacula-director-5.2.13/updatedb
|
||||
|
||||
mlocate-0.26-8.el7.x86_64 : An utility for finding files by name
|
||||
Repo : local_base
|
||||
Matched from:
|
||||
Filename : /usr/bin/updatedb
|
||||
```
|
||||
|
||||
笔者使用星号的原因是'yum whatprovides'使用路径去匹配文件。笔者不确定文件在哪里，所以使用星号去指代任意路径。
|
||||
|
||||
当然YUM还有很多其他的可选项。这里笔者希望你能够自己查看YUM的手册来找到其他额外的可选额。
|
||||
|
||||
[Dandified Yum (DNF)][7]是YUM的下一代接班人。从Fedora 18开始被作为包管理器引入系统，不过它并没有被企业版所采用，所以它只在Fedora（以及变种）上占据了主导地位。DNF的用法和YUM几乎一模一样，它主要是用来解决性能问题，晦涩无说明的API，缓慢的依赖解析以及偶尔的高内存占用。DNF是作为YUM的直接替代品来开发的，因此这里笔者就不重复它的用法了，你只用简单的将YUM替换为DNF就行了。
|
||||
|
||||
###使用Zypper
|
||||
|
||||
[Zypper][8]是用来管理RPM包的另外一个包管理器。这个包管理器主要用于[SUSE][9]（和[openSUSE][10]）,在[MeeGo][11],[Sailfish OS][12],[Tizen][13]上也有使用。它在2006年被开发出来，也已经经过了多次迭代发布。除了作为[YaST][14]的系统管理工具和有些用户认为它比YUM要快之外也没有什么好多说的。
|
||||
|
||||
Zypper's使用与YUM非常相像。它被用来搜索，更新，安装和删除包，请使用如下命令：
|
||||
|
||||
```
|
||||
zypper search kate
|
||||
zypper update
|
||||
zypper install kate
|
||||
zypper remove kate
|
||||
```
|
||||
|
||||
使用Zypper的系统在添加软件仓库的方面的做法上有些许不同，与上述讨论的包管理器不同，zypper使用包管理器本身来添加软件仓库。最通用的方法是通过一个URL，但是Zypper也支持从仓库文件里导入。
|
||||
|
||||
```
|
||||
suse:~ # zypper addrepo http://download.videolan.org/pub/vlc/SuSE/15.0 vlc
|
||||
Adding repository 'vlc' [done]
|
||||
Repository 'vlc' successfully added
|
||||
|
||||
Enabled : Yes
|
||||
Autorefresh : No
|
||||
GPG Check : Yes
|
||||
URI : http://download.videolan.org/pub/vlc/SuSE/15.0
|
||||
Priority : 99
|
||||
```
|
||||
|
||||
你也能用相似的手段来删除软件仓库：
|
||||
|
||||
```
|
||||
suse:~ # zypper removerepo vlc
|
||||
Removing repository 'vlc' ...................................[done]
|
||||
Repository 'vlc' has been removed.
|
||||
```
|
||||
|
||||
使用'zypper repos'命令来查看当前系统上的软件仓库的状态：
|
||||
|
||||
```
|
||||
suse:~ # zypper repos
|
||||
Repository priorities are without effect. All enabled repositories share the same priority.
|
||||
|
||||
# | Alias | Name | Enabled | GPG Check | Refresh
|
||||
---|---------------------------|-----------------------------------------|---------|-----------|--------
|
||||
1 | repo-debug | openSUSE-Leap-15.0-Debug | No | ---- | ----
|
||||
2 | repo-debug-non-oss | openSUSE-Leap-15.0-Debug-Non-Oss | No | ---- | ----
|
||||
3 | repo-debug-update | openSUSE-Leap-15.0-Update-Debug | No | ---- | ----
|
||||
4 | repo-debug-update-non-oss | openSUSE-Leap-15.0-Update-Debug-Non-Oss | No | ---- | ----
|
||||
5 | repo-non-oss | openSUSE-Leap-15.0-Non-Oss | Yes | ( p) Yes | Yes
|
||||
6 | repo-oss | openSUSE-Leap-15.0-Oss | Yes | ( p) Yes | Yes
|
||||
```
|
||||
|
||||
'zypper'甚至还有和YUM相同的功能:搜索包存在哪个实用程序。和YUM有所不同的是，它在命令行里使用破折号（但是这个搜索方法现在被废除了...）
|
||||
|
||||
```
|
||||
localhost:~ # zypper what-provides kate
|
||||
Command 'what-provides' is replaced by 'search --provides --match-exact'.
|
||||
See 'help search' for all available options.
|
||||
Loading repository data...
|
||||
Reading installed packages...
|
||||
|
||||
S | Name | Summary | Type
|
||||
---|------|----------------------|------------
|
||||
i+ | Kate | Advanced Text Editor | application
|
||||
i | kate | Advanced Text Editor | package
|
||||
```
|
||||
|
||||
YUM，DNF和Zypper三剑客拥有的功能比在这篇小文里讨论的要多得多，请查看官方文档来得到更深入的信息。
|
||||
|
||||
###基于Debian 的包管理器
|
||||
|
||||
作为一个现今仍在被积极维护的历史悠久的Linux发布版本，Debian的包管理系统和基于RPM的系统的包管理系统非常类似。它使用扩展名为’.deb‘的包，这种文件能被一个叫做dpkg的工具所管理。dpgk同RPM非常相似，它被设计成用来管理在存在于本地（硬盘）的包。它不会去做包依赖关系解析（它会做依赖关系检查，不过仅此而已），而且在同远程软件仓库交互上也并无可靠的途径，为了提高用户体验并便于使用，Debian项目开始了一个软件项目：Deity,最终这个代号被丢弃并改成了现在的[Advanced Pack Tool(APT)][15]
|
||||
|
||||
在1998年，APT测试版本发布（甚至早于1999年的Debian 2.1正式版发布），许多用户认为APT是基于Debian系统的默认包管理器。APT使用了和RPM一样的风格来管理，不过和YUM使用单独的’.repo‘不同，’apt‘曾经使用’/etc/apt/sources.list‘文件来管理软件仓库，后来的变成也可以使用’/etc/apt/sources.d‘目录来管理。如同基于RPM的系统一样，你也有很多很多选项配置来完成同样的事情。你可以编辑/创建前述的文件，或者使用图形界面来完成上述工作（如Ubuntu的’Software & Updates‘），为了给所有的Linux发行版统一的待遇，笔者将会只介绍命令行的选项。
|
||||
要想不直接编辑文件内容而直接增加软件仓库的话，用如下命令：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-add-repository "deb http://APT.spideroak.com/ubuntu-spideroak-hardy/ release restricted"
|
||||
|
||||
```
|
||||
|
||||
这个命令将会在’/etc/apt/sources.list.d‘目录里创建一个’spideroakone.list‘文件。显而易见，文件里的内容依赖于所添加的软件仓库，如果你想加一个个人软件包存档的话（译注：PPA），你可以用如下的办法：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-add-repository ppa:gnome-desktop
|
||||
|
||||
```
|
||||
|
||||
注意： Debian并不支持本地PPAs。
|
||||
|
||||
在添加了一个软件仓库后，需要通知Debian有一个新的仓库可以用来搜索包，可以运行’apt-get update‘来完成。
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get update
|
||||
Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]
|
||||
Hit:2 http://APT.spideroak.com/ubuntu-spideroak-hardy release InRelease
|
||||
Hit:3 http://ca.archive.ubuntu.com/ubuntu xenial InRelease
|
||||
Get:4 http://ca.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
|
||||
Get:5 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages [517 kB]
|
||||
Get:6 http://security.ubuntu.com/ubuntu xenial-security/main i386 Packages [455 kB]
|
||||
Get:7 http://security.ubuntu.com/ubuntu xenial-security/main Translation-en [221 kB]
|
||||
...
|
||||
|
||||
Fetched 6,399 kB in 3s (2,017 kB/s)
|
||||
Reading package lists... Done
|
||||
```
|
||||
|
||||
现在新的软件仓库已经在你的系统里安装并更新好了，你可以用’apt-cache‘来搜索你想要的包了。
|
||||
|
||||
```
|
||||
user@ubuntu:~$ apt-cache search kate
|
||||
aterm-ml - Afterstep XVT - a VT102 emulator for the X window system
|
||||
frescobaldi - Qt4 LilyPond sheet music editor
|
||||
gitit - Wiki engine backed by a git or darcs filestore
|
||||
jedit - Plugin-based editor for programmers
|
||||
kate - powerful text editor
|
||||
kate-data - shared data files for Kate text editor
|
||||
kate-dbg - debugging symbols for Kate
|
||||
katepart - embeddable text editor component
|
||||
```
|
||||
|
||||
要安装‘kate’,简单的运行下面的命令：
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get install kate
|
||||
|
||||
```
|
||||
To remove a package, use `apt-get remove`:
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get remove kate
|
||||
|
||||
```
|
||||
|
||||
APT并没有提供一个类似于'yum whatprovides'的功能，如果你想深入包内部去确定一个特定的文件的话，也有一些别的方法能帮你完成这个目标，
|
||||
|
||||
如： 用dpkg
|
||||
|
||||
```
|
||||
user@ubuntu:~$ dpkg -S /bin/ls
|
||||
coreutils: /bin/ls
|
||||
```
|
||||
或者： apt-file
|
||||
|
||||
```
|
||||
user@ubuntu:~$ sudo apt-get install apt-file -y
|
||||
|
||||
user@ubuntu:~$ sudo apt-file update
|
||||
|
||||
user@ubuntu:~$ apt-file search kate
|
||||
```
|
||||
|
||||
'apt-file search'的问题是和‘yum whatprovides’不同，因为自动添加了通配符搜索而输出过于详细，在结果里包括了所有包含有‘kate’的结果。
|
||||
|
||||
```
|
||||
kate: /usr/bin/kate
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katebacktracebrowserplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katebuildplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katecloseexceptplugin.so
|
||||
kate: /usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/katectagsplugin.so
|
||||
```
|
||||
|
||||
上面这些例子大部分都使用了‘apt-get’.请注意现今大多数的Ubuntu教程里都径直使用了'apt'. 单独一个‘apt’是用来实现最常用的那些APT命令的。APT看上去是用来整合那些被分散在'apt-get','apt-cache'以及其他一些命令的的功能的。它还加上了一些额外的改进，如色彩，进度条以及其他一些小功能。上述的常用apt功能都能被apt替代，但是并不是所有的基于Debian的系统都能使用‘apt’接受安全包补丁的，你有可能要安装额外的包的实现上述功能。
|
||||
|
||||
###基于Arch的包管理器
|
||||
|
||||
[Arch Linux][16]使用称为[packman][17]的包管理器。和‘.deb’以及'.rpm’不同，它使用更为传统的压缩包形式'.tar.xz'。这帮助Arch Linux包能够使用更小的包尺寸。自从2002年发布以来，pacman一直在稳定发布和改善。使用它最大的好处之一是他支持[Arch Build System][18],一个从源代码级别构建包的构建系统。这个构建系统使用一个叫PKGBUILD的文件，这个文件包含了如版本号，发布号，依赖等等的元数据，以及为编译一个遵守Arch Linux需求的包所需要的带有必须编译选项的脚本。而编译的结果就是前文所提的被pacman所使用的‘.tar.xz’的文件。
|
||||
|
||||
上述的这套系统技术上导致了[Arch User Respository][19](AUR)的产生，这是一个社区驱动的软件仓库，仓库里包括有PKGBUILD文件以及支持的补丁包或脚本。这给Arch Linux带了无穷无尽的软件资源。最为明显的好处是如果一个用户（或开发者）希望他开发的软件能被广大公众所使用，他不必通过官方途径去在主流软件仓库获得许可。而不利之处则是它必须将依赖社区的流程，类似于[Docker Hub][20]，Canonical's Snap Packages(译注： Canonical是Ubuntu的发行公司)，或者其他相似的机制。有很多特定于AUR的包管理器能被用来从ARU里的PGKBUILD文件下载，编译，安装，下面我们来仔细看看怎么做。
|
||||
|
||||
###使用pacman和官方软件仓库
|
||||
|
||||
Arch的主要包管理器：pacman，使用标识位而不是像’yum‘或’apt‘一样使用命令词。例如，要搜索一个包，你要用'pacman -Ss'。和Linux上别的命令一样，你可以找到pacman 的’manpage‘和在线帮助。pacman大多数的命令都使用了同步(-S)这个标识位。例如：
|
||||
|
||||
```
|
||||
user@arch ~ $ pacman -Ss kate
|
||||
|
||||
extra/kate 18.04.2-2 (kde-applications kdebase)
|
||||
Advanced Text Editor
|
||||
extra/libkate 0.4.1-6 [installed]
|
||||
A karaoke and text codec for embedding in ogg
|
||||
extra/libtiger 0.3.4-5 [installed]
|
||||
A rendering library for Kate streams using Pango and Cairo
|
||||
extra/ttf-cheapskate 2.0-12
|
||||
TTFonts collection from dustimo.com
|
||||
community/haskell-cheapskate 0.1.1-100
|
||||
Experimental markdown processor.
|
||||
```
|
||||
|
||||
Arch也使用和别的包管理器类似的软件仓库。在上面的输出中，搜索结果前面有标明它是从哪个仓库里搜索到的（这里是'extra/'和’community/‘）。同Red Hat和Debian系统一样，Arch依靠用户将软件仓库的信息加入到一个特定的文件里：/etc/pacman.conf。下面的例子非常接近一个仓库系统。笔者还打开了'[multilib]'仓库来支持Steam:
|
||||
|
||||
```
|
||||
[options]
|
||||
Architecture = auto
|
||||
|
||||
Color
|
||||
CheckSpace
|
||||
|
||||
SigLevel = Required DatabaseOptional
|
||||
LocalFileSigLevel = Optional
|
||||
|
||||
[core]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[extra]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[community]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
|
||||
[multilib]
|
||||
Include = /etc/pacman.d/mirrorlist
|
||||
```
|
||||
|
||||
你也可以指定在’pacman.conf‘里指定具体的URL。这个功能可以用来确定在某一时刻所有的包来自一个确定的地方，比如，如果一个安装包存在严重的功能缺陷并且很不幸它恰好还有几个包依赖，你能及时回滚到一个安全点，如果你已经在’pacman.conf‘里加入了具体的URL的话，你就用用这个命令降级你的系统。
|
||||
|
||||
```
|
||||
[core]
|
||||
Server=https://archive.archlinux.org/repos/2017/12/22/$repo/os/$arch
|
||||
```
|
||||
|
||||
和Debian系统一样，Arch并不会自动更新它的本地仓库。你可以用下面的命令来刷新包管理器的数据库：
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Sy
|
||||
|
||||
:: Synchronizing package databases...
|
||||
core 130.2 KiB 851K/s 00:00 [##########################################################] 100%
|
||||
extra 1645.3 KiB 2.69M/s 00:01 [##########################################################] 100%
|
||||
community 4.5 MiB 2.27M/s 00:02 [##########################################################] 100%
|
||||
multilib is up to date
|
||||
```
|
||||
|
||||
你可以看到在上述的输出中，'pacman'认为multilib包数据库是更新到最新状态的。如果你认为这个结果不正确的话，你可以强制运行刷新:pacman -Syy。如果你想升级你的整个系统的话（不包括从AUR安装的包），你可以运行’pacman -Syu‘:
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Syu
|
||||
|
||||
:: Synchronizing package databases...
|
||||
core is up to date
|
||||
extra is up to date
|
||||
community is up to date
|
||||
multilib is up to date
|
||||
:: Starting full system upgrade...
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (45) ceph-13.2.0-2 ceph-libs-13.2.0-2 debootstrap-1.0.105-1 guile-2.2.4-1 harfbuzz-1.8.2-1 harfbuzz-icu-1.8.2-1 haskell-aeson-1.3.1.1-20
|
||||
haskell-attoparsec-0.13.2.2-24 haskell-tagged-0.8.6-1 imagemagick-7.0.8.4-1 lib32-harfbuzz-1.8.2-1 lib32-libgusb-0.3.0-1 lib32-systemd-239.0-1
|
||||
libgit2-1:0.27.2-1 libinput-1.11.2-1 libmagick-7.0.8.4-1 libmagick6-6.9.10.4-1 libopenshot-0.2.0-1 libopenshot-audio-0.1.6-1 libosinfo-1.2.0-1
|
||||
libxfce4util-4.13.2-1 minetest-0.4.17.1-1 minetest-common-0.4.17.1-1 mlt-6.10.0-1 mlt-python-bindings-6.10.0-1 ndctl-61.1-1 netctl-1.17-1
|
||||
nodejs-10.6.0-1
|
||||
|
||||
Total Download Size: 2.66 MiB
|
||||
Total Installed Size: 879.15 MiB
|
||||
Net Upgrade Size: -365.27 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
在前面提到的降级系统的情景中，你可以运行’pacman -Syyuu‘来强行降级系统。你必须重视这一点：虽然在大多数情况下这不会引起问题，但是这种可能性还是存在，即降级一个包或几个包将会引起级联传播的失败并会将你的系统处于不一致的状态（译注：即系统进入无法正常使用的状态），请务必小心！
|
||||
|
||||
运行’pacman -S kate‘来安装一个包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -S kate
|
||||
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (7) editorconfig-core-c-0.12.2-1 kactivities-5.47.0-1 kparts-5.47.0-1 ktexteditor-5.47.0-2 syntax-highlighting-5.47.0-1 threadweaver-5.47.0-1
|
||||
kate-18.04.2-2
|
||||
|
||||
Total Download Size: 10.94 MiB
|
||||
Total Installed Size: 38.91 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
你可以运行’pacman -R kate‘来删除一个包。这将会只删除这个包自身而不会去删除它的依赖包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -S kate
|
||||
|
||||
checking dependencies...
|
||||
|
||||
Packages (1) kate-18.04.2-2
|
||||
|
||||
Total Removed Size: 20.30 MiB
|
||||
|
||||
:: Do you want to remove these packages? [Y/n]
|
||||
```
|
||||
|
||||
如果你想删除没有被其他包依赖的包，你可以运行‘pacman -Rs:’
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Rs kate
|
||||
|
||||
checking dependencies...
|
||||
|
||||
Packages (7) editorconfig-core-c-0.12.2-1 kactivities-5.47.0-1 kparts-5.47.0-1 ktexteditor-5.47.0-2 syntax-highlighting-5.47.0-1 threadweaver-5.47.0-1
|
||||
kate-18.04.2-2
|
||||
|
||||
Total Removed Size: 38.91 MiB
|
||||
|
||||
:: Do you want to remove these packages? [Y/n]
|
||||
```
|
||||
|
||||
在笔者看来，Pacman是搜索一个指定实用程序中的指定包的最齐全的工具。如上所示，'YUM'和'APT'都依赖硬编码‘路径’去搜索到有用的结果而Pacman则做了一些智能的猜测，它会去猜测你最有可能想搜索的包。
|
||||
|
||||
```
|
||||
user@arch ~ $ sudo pacman -Fs updatedb
|
||||
core/mlocate 0.26.git.20170220-1
|
||||
usr/bin/updatedb
|
||||
|
||||
user@arch ~ $ sudo pacman -Fs kate
|
||||
extra/kate 18.04.2-2
|
||||
usr/bin/kate
|
||||
```
|
||||
|
||||
###使用AUR
|
||||
|
||||
有很多流行的AUR包管理器助手。其中'yaourt' 和'pacaur' 颇为流行。不过，这两个项目已经被列为不继续开发以及有已知的问题未解决[Arch Wiki][21]。因为这个原因，这里直接讨论‘aurman’，除了会搜索AUR以及包含几个有帮助的（其实很危险）的选项之外，它的工作机制和'pacman'极其类似。从AUR安装一个包将会初始化包维护者的构建脚本。你将会被要求输入几次授权以便让程序继续进行下去（为了简短起见，笔者截断了输出）。
|
||||
|
||||
```
|
||||
aurman -S telegram-desktop-bin
|
||||
~~ initializing aurman...
|
||||
~~ the following packages are neither in known repos nor in the aur
|
||||
...
|
||||
~~ calculating solutions...
|
||||
|
||||
:: The following 1 package(s) are getting updated:
|
||||
aur/telegram-desktop-bin 1.3.0-1 -> 1.3.9-1
|
||||
|
||||
?? Do you want to continue? Y/n: Y
|
||||
|
||||
~~ looking for new pkgbuilds and fetching them...
|
||||
Cloning into 'telegram-desktop-bin'...
|
||||
|
||||
remote: Counting objects: 301, done.
|
||||
remote: Compressing objects: 100% (152/152), done.
|
||||
remote: Total 301 (delta 161), reused 286 (delta 147)
|
||||
Receiving objects: 100% (301/301), 76.17 KiB | 639.00 KiB/s, done.
|
||||
Resolving deltas: 100% (161/161), done.
|
||||
?? Do you want to see the changes of telegram-desktop-bin? N/y: N
|
||||
|
||||
[sudo] password for user:
|
||||
|
||||
...
|
||||
==> Leaving fakeroot environment.
|
||||
==> Finished making: telegram-desktop-bin 1.3.9-1 (Thu 05 Jul 2018 11:22:02 AM EDT)
|
||||
==> Cleaning up...
|
||||
loading packages...
|
||||
resolving dependencies...
|
||||
looking for conflicting packages...
|
||||
|
||||
Packages (1) telegram-desktop-bin-1.3.9-1
|
||||
|
||||
Total Installed Size: 88.81 MiB
|
||||
Net Upgrade Size: 5.33 MiB
|
||||
|
||||
:: Proceed with installation? [Y/n]
|
||||
```
|
||||
|
||||
依照你所安装的包的复杂性程度的高低，有时你将会被要求给出进一步的输入确定，为了避免这些反复的输入，'aurman' 允许你使用'--noconfirm'和'--noedit'选项。这相当于说‘接受所有的预定设置，并相信包管理器不会干坏事。**使用这两个选项时请务必小心！！**，虽然这些选项本身不太会破坏你的系统，你也不能盲目的接受他人的脚本程序。
|
||||
|
||||
|
||||
###总结
|
||||
|
||||
这篇文章当然只能触及包管理器的皮毛。还有很多别的包管理器笔者没有在这片文章里谈及。有些Linux发布版，如Ubuntu或Elementary OS,已经在图形版的包管理器的开发上有了长远的进展。
|
||||
|
||||
如果你对包管理器的更高级功能有进一步的兴趣，请在评论区留言，笔者很乐意进一步的写一写相关的文章。
|
||||
|
||||
###附录
|
||||
```
|
||||
# search for packages
|
||||
yum search <package>
|
||||
dnf search <package>
|
||||
zypper search <package>
|
||||
apt-cache search <package>
|
||||
apt search <package>
|
||||
pacman -Ss <package>
|
||||
|
||||
# install packages
|
||||
yum install <package>
|
||||
dnf install <package>
|
||||
zypper install <package>
|
||||
apt-get install <package>
|
||||
apt install <package>
|
||||
pacman -Ss <package>
|
||||
|
||||
# update package database, not required by yum, dnf and zypper
|
||||
apt-get update
|
||||
apt update
|
||||
pacman -Sy
|
||||
|
||||
# update all system packages
|
||||
yum update
|
||||
dnf update
|
||||
zypper update
|
||||
apt-get upgrade
|
||||
apt upgrade
|
||||
pacman -Su
|
||||
|
||||
# remove an installed package
|
||||
yum remove <package>
|
||||
dnf remove <package>
|
||||
apt-get remove <package>
|
||||
apt remove <package>
|
||||
pacman -R <package>
|
||||
pacman -Rs <package>
|
||||
|
||||
# search for the package name containing specific file or folder
|
||||
yum whatprovides *<binary>
|
||||
dnf whatprovides *<binary>
|
||||
zypper what-provides <binary>
|
||||
zypper search --provides <binary>
|
||||
apt-file search <binary>
|
||||
pacman -Sf <binary>
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/7/evolution-package-managers
|
||||
|
||||
作者：[Steve Ovens][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[DavidChenLiang](https://github.com/davidchenliang)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/stratusss
|
||||
[1]:https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures
|
||||
[2]:https://en.wikipedia.org/wiki/Yum_(software)
|
||||
[3]:https://fedoraproject.org/wiki/DNF
|
||||
[4]:https://en.wikipedia.org/wiki/Rpm_(software)
|
||||
[5]:https://en.wikipedia.org/wiki/Yellow_Dog_Linux
|
||||
[6]:https://searchdatacenter.techtarget.com/definition/Yellowdog-Updater-Modified-YUM
|
||||
[7]:https://en.wikipedia.org/wiki/DNF_(software)
|
||||
[8]:https://en.opensuse.org/Portal:Zypper
|
||||
[9]:https://www.suse.com/
|
||||
[10]:https://www.opensuse.org/
|
||||
[11]:https://en.wikipedia.org/wiki/MeeGo
|
||||
[12]:https://sailfishos.org/
|
||||
[13]:https://www.tizen.org/
|
||||
[14]:https://en.wikipedia.org/wiki/YaST
|
||||
[15]:https://en.wikipedia.org/wiki/APT_(Debian)
|
||||
[16]:https://www.archlinux.org/
|
||||
[17]:https://wiki.archlinux.org/index.php/pacman
|
||||
[18]:https://wiki.archlinux.org/index.php/Arch_Build_System
|
||||
[19]:https://aur.archlinux.org/
|
||||
[20]:https://hub.docker.com/
|
||||
[21]:https://wiki.archlinux.org/index.php/AUR_helpers#Discontinued_or_problematic
|
||||
@ -1,28 +1,25 @@
|
||||
Translating by MjSeven
|
||||
|
||||
|
||||
How to display data in a human-friendly way on Linux
|
||||
在 Linux 中如何以人性化的方式显示数据
|
||||
======
|
||||
|
||||
|
||||
|
||||
Not everyone thinks in binary or wants to mentally insert commas into large numbers to come to grips with the sizes of their files. So, it's not surprising that Linux commands have evolved over several decades to incorporate more human-friendly ways of displaying information to its users. In today’s post, we look at some of the options provided by various commands that make digesting data just a little easier.
|
||||
不是每个人都以二进制方式思考，他们不想在大脑中插入逗号来处理大量数字并获得文件的大小。因此，Linux 命令在过去的几十年里不断发展，以更人性化的方式向用户显示信息，这一点也不奇怪。在今天的文章中，我们将看一看各种命令所提供的一些选项，它们使得数据变得更容易理解。
|
||||
|
||||
### Why not default to friendly?
|
||||
### 为什么默认显示不更友好一些？
|
||||
|
||||
If you’re wondering why human-friendliness isn’t the default –- we humans are, after all, the default users of computers — you might be asking yourself, “Why do we have to go out of our way to get command responses that will make sense to everyone?” The answer is primarily that changing the default output of commands would likely interfere with numerous other processes that were built to expect the default responses. Other tools, as well as scripts, that have been developed over the decades might break in some very ugly ways if they were suddenly fed output in a very different format than what they were built to expect.
|
||||
如果你想知道为什么默认不显示得更人性化，原因是：我们人类毕竟是计算机的默认用户（to 校正：这里分很不理解，感觉不对，既然人类是默认用户，那么为什么不人性化呢）。你可能会问自己：“为什么我们不竭尽全力去获得对每个人都有意义的命令的响应？”答案是：改变命令的默认输出可能会干扰许多其它进程，这些进程是在期望默认响应之上构建的。其它的工具，以及过去几十年开发的脚本，如果突然以一种完全不同的格式输出，而不是它们过去所期望的那样，可能会被一种非常丑陋的方式破坏。
|
||||
|
||||
It’s probably also true that some of us might prefer to see all of the digits in our file sizes — 1338277310 instead of 1.3G. In any case, switching defaults could be very disruptive, while promoting some easy options for more human-friendly responses only involves us learning some command options.
|
||||
说真的，也许我们中的一些人可能更愿意看文件大小中的所有数字，即 1338277310 而不是 1.3G。在任何情况下，切换默认值都可能造成破坏，但是为更加人性化的响应提供一些简单的选项只会让我们学习一些命令选项。
|
||||
|
||||
### Commands for displaying human-friendly data
|
||||
### 可以显示人性化数据的命令
|
||||
|
||||
What are some of the easy options for making the output of Unix commands a little easier to parse? Let's check some command by command.
|
||||
有哪些简单的选项可以使 Unix 命令的输出更容易解析呢？让我们来看一些命令。
|
||||
|
||||
#### top
|
||||
|
||||
You may not have noticed this, but you can change the display of overall memory usage in top by typing " **E** " (i.e., capital E) once top is running. Successive presses will change the numeric display from KiB to MiB to GiB to TiB to PiB to EiB and back to KiB.
|
||||
你可能没有注意到这个命令，但是在 top 命令中，你可以通过输入 “**E**”（大写字母 E）来更改显示全部内存使用的方式。连续按下将数字显示从 KiB 到 MiB, 再到 GiB, 接着是 TiB, PiB, EiB，最后回到 KiB。
|
||||
|
||||
OK with those units? These and a couple more are defined here:
|
||||
认识这些单位吧？这里有一组定义：
|
||||
```
|
||||
2**10 = 1,024 = 1 KiB (kibibyte)
|
||||
2**20 = 1,048,576 = 1 MiB (mebibyte)
|
||||
@ -35,14 +32,14 @@ OK with those units? These and a couple more are defined here:
|
||||
|
||||
```
|
||||
|
||||
These units are closely related to kilobytes, megabytes, and gigabytes, etc. But, while close, there's still a significant difference between them. One set is based on powers of 10 and the other powers of 2. Comparing kilobytes and kibibytes, for example, we can see how they diverge:
|
||||
这些单位与千字节，兆字节和千兆字节密切相关。虽然它们很接近，但是它们之间仍有很大的区别：一组是基于 10 的幂，另一组是基于 2 的幂。例如，比较千字节和千比字节，我们可以看看它们不同点：
|
||||
```
|
||||
KB = 1000 = 10**3
|
||||
KiB = 1024 = 2**10
|
||||
|
||||
```
|
||||
|
||||
Here's an example of top output using the default display in KiB:
|
||||
以下是 top 命令输出示例，使用 KiB 为单位默认显示：
|
||||
```
|
||||
top - 10:49:06 up 5 days, 35 min, 1 user, load average: 0.05, 0.04, 0.01
|
||||
Tasks: 158 total, 1 running, 118 sleeping, 0 stopped, 0 zombie
|
||||
@ -52,7 +49,7 @@ KiB Swap: 2097148 total, 2097148 free, 0 used. 5407432 avail Mem
|
||||
|
||||
```
|
||||
|
||||
After one press of an E, it changes to MiB:
|
||||
在按下 E 之后，单位变成了 MiB：
|
||||
```
|
||||
top - 10:49:31 up 5 days, 36 min, 1 user, load average: 0.03, 0.04, 0.01
|
||||
Tasks: 158 total, 2 running, 118 sleeping, 0 stopped, 0 zombie
|
||||
@ -62,7 +59,7 @@ MiB Swap: 2047.996 total, 2047.996 free, 0.000 used. 5280.684 avail Mem
|
||||
|
||||
```
|
||||
|
||||
After a second E, we get GiB:
|
||||
再次按下 E，单位变为 GiB：
|
||||
```
|
||||
top - 10:49:49 up 5 days, 36 min, 1 user, load average: 0.02, 0.03, 0.01
|
||||
Tasks: 158 total, 1 running, 118 sleeping, 0 stopped, 0 zombie
|
||||
@ -72,7 +69,7 @@ GiB Swap: 2.000 total, 2.000 free, 0.000 used. 5.157 avail Mem
|
||||
|
||||
```
|
||||
|
||||
You can also change the numbers displaying per-process memory usage by pressing the letter “ **e** ”. It will change from the default of KiB to MiB to GiB to TiB to PiB (expect to see LOTS of zeroes!) and back. Here's some top output after one press of an " **e** ":
|
||||
你还可以通过按字母 “**e**” 来更改为显示每个进程使用内存的数字单位。它将从默认的 KiB 到 MiB，再到 GiB, TiB，接着到 PiB（期望看到很多0 (to 校正者：意思是以 PB 为单位前面很多 0)），然后返回 KiB。下面是按了一下 “**e**” 之后的 top 输出：
|
||||
```
|
||||
top - 08:45:28 up 4 days, 22:32, 1 user, load average: 0.02, 0.03, 0.00
|
||||
Tasks: 167 total, 1 running, 118 sleeping, 0 stopped, 0 zombie
|
||||
@ -90,7 +87,7 @@ KiB Swap: 2097148 total, 2097148 free, 0 used. 5406396 avail Mem
|
||||
|
||||
#### du
|
||||
|
||||
The du command, which shows how much disk space files or directories use, adjusts the sizes to the most appropriate measurement if the **-h** option is used. By default, it reports in kilobytes.
|
||||
du 命令显示磁盘空间文件或目录使用了多少，如果使用 **-h** 选项，则将输出大小调整为最合适的单位。默认情况下，它以千字节（KB）为单位。
|
||||
```
|
||||
$ du camper*
|
||||
360 camper_10.jpg
|
||||
@ -105,7 +102,7 @@ $ du -h camper*
|
||||
|
||||
#### df
|
||||
|
||||
The df command also offers a -h option. Note in the example below how sizes are reported in both gigabytes and megabytes.
|
||||
df 命令也提供了一个 -h 选项。请注意在下面的示例中是如何以千兆字节（GB）和兆字节（MB）输出的：
|
||||
```
|
||||
$ df -h | grep -v loop
|
||||
Filesystem Size Used Avail Use% Mounted on
|
||||
@ -121,7 +118,7 @@ tmpfs 596M 0 596M 0% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
The command below uses the **-h** option, but also includes **-T** to display the type of file system we are looking at.
|
||||
下面的命令使用了 **-h** 选项，同时使用 **-T** 选项来显示我们正在查看的文件系统的类型。
|
||||
```
|
||||
$ df -hT /mnt2
|
||||
Filesystem Type Size Used Avail Use% Mounted on
|
||||
@ -131,7 +128,7 @@ Filesystem Type Size Used Avail Use% Mounted on
|
||||
|
||||
#### ls
|
||||
|
||||
Even ls gives us the option of adjusting size displays to the measurements that are the most reasonable.
|
||||
即使是 ls，它也为我们提供了调整大小显示的选项，保证是最合理的。
|
||||
```
|
||||
$ ls -l camper*
|
||||
-rw-rw-r-- 1 shs shs 365091 Jul 14 19:42 camper_10.jpg
|
||||
@ -146,7 +143,7 @@ $ ls -lh camper*
|
||||
|
||||
#### free
|
||||
|
||||
The free command allows you to report memory usage in bytes, kilobytes, megabytes, and gigabytes.
|
||||
free 命令允许你以字节（B），千字节（KB），兆字节（MB）和千兆字节（GB）为单位查看内存使用情况。
|
||||
```
|
||||
$ free -b
|
||||
total used free shared buff/cache available
|
||||
@ -169,7 +166,7 @@ Swap: 1 0 1
|
||||
|
||||
#### tree
|
||||
|
||||
While not related to file or memory measurements, the tree command also provides very human-friendly view of files by displaying them in a hierarchical display to illustrate how the files are organized. This kind of display can be very useful when trying to get an idea for how the contents of a directory are arranged.
|
||||
虽然 tree 命令与文件或内存计算无关，但它也提供了非常人性化的文件视图，它分层显示文件以说明文件是如何组织的。当你试图了解如何安排目录内容时，这种显示方式非常有用。
|
||||
```
|
||||
$ tree
|
||||
.g to
|
||||
@ -190,7 +187,7 @@ $ tree
|
||||
|
||||
#### stat
|
||||
|
||||
The stat command is another that displays information in a very human-friendly format. It provides a lot more metadata on files, including the file sizes in bytes and blocks, the file types, device and inode, owner and group (names and numeric IDs), file permissions in both numeric and rwx format and the dates the file was last accessed and modified. In some circumstances, it might also display when the file was initially created.
|
||||
stat 命令是另一个以非常人性化的格式显示信息的命令。它提供了更多关于文件的元数据，包括文件大小（以字节和块为单位），文件类型，设备和 inode（索引节点），文件所有者和组（名称和数字 ID），以数字和 rwx 格式显示的文件权限以及文件的最后访问和修改日期。在某些情况下，它也可能显示最初创建文件的时间。
|
||||
```
|
||||
$ stat camper*
|
||||
File: camper_10.jpg
|
||||
@ -212,11 +209,12 @@ Change: 2018-07-14 19:41:46.882024039 -0400
|
||||
|
||||
```
|
||||
|
||||
### Wrap-up
|
||||
### 总结
|
||||
|
||||
Linux provides many command options that can make their output easier for users to understand or compare. For many commands, the **-h** option brings up the friendlier output format. For others, you might have to specify how you'd prefer to see your output by using some specific option or pressing a key as with **top**. I hope that some of these choices will make your Linux systems seem just a little friendlier.
|
||||
Linux 命令提供了许多选项，可以让用户更容易理解或比较它们的输出。对于许多命令，**-h** 选项会显示更友好的输出格式。对于其它的，你可能必须通过使用某些特定选项或者按下某个键来查看你希望的输出。我希望这其中一些选项会让你的 Linux 系统看起来更友好一点。
|
||||
|
||||
加入[Facebook][1] 和 [LinkedIn][2] 上的网络世界社区，一起来评论重要的话题吧。
|
||||
|
||||
Join the Network World communities on [Facebook][1] and [LinkedIn][2] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -224,7 +222,7 @@ via: https://www.networkworld.com/article/3296631/linux/displaying-data-in-a-hum
|
||||
|
||||
作者：[Sandra Henry-Stocker][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
译者：[MjSeven](https://github.com/MjSeven)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
@ -0,0 +1,178 @@
|
||||
在 Linux 中使用 top 命令的建议
|
||||
======
|
||||
|
||||
|
||||
|
||||
尝试找出你的机器正在运行的是什么程序，以及哪个进程耗尽了内存导致运行非常非常慢——这些都是 `top` 命令所能胜任的任务。
|
||||
|
||||
`top` 是一个非常有用的程序，其作用类似于 Windows 任务管理器或 MacOS 的活动监视器。在 *nix 机器上运行 `top` 将显示系统上运行的进程的实时运行视图。
|
||||
|
||||
```
|
||||
$ top
|
||||
```
|
||||
|
||||
取决于你正在运行的 `top` 版本，你将获得如下所示的内容：
|
||||
|
||||
```
|
||||
top - 08:31:32 up 1 day, 4:09, 0 users, load average: 0.20, 0.12, 0.10
|
||||
Tasks: 3 total, 1 running, 2 sleeping, 0 stopped, 0 zombie
|
||||
%Cpu(s): 0.5 us, 0.3 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
|
||||
KiB Mem: 4042284 total, 2523744 used, 1518540 free, 263776 buffers
|
||||
KiB Swap: 1048572 total, 0 used, 1048572 free. 1804264 cached Mem
|
||||
|
||||
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
|
||||
1 root 20 0 21964 3632 3124 S 0.0 0.1 0:00.23 bash
|
||||
193 root 20 0 123520 29636 8640 S 0.0 0.7 0:00.58 flask
|
||||
195 root 20 0 23608 2724 2400 R 0.0 0.1 0:00.21 top
|
||||
```
|
||||
|
||||
你所用的 `top` 版本可能跟这个看起来不一样，特别是在显示的列上。
|
||||
|
||||
### 如何阅读输出的内容
|
||||
|
||||
你可以根据输出判断您正在运行的内容，但尝试去解释结果你可能会有些困惑。
|
||||
|
||||
前几行包含一堆统计信息（详细信息），后跟一个包含结果列表的表（列表）。 让我们从后者开始吧。
|
||||
|
||||
### 列表
|
||||
|
||||
这些是正运行在系统上的进程。默认按 CPU 使用率降序排序。这意味着在列表顶部的程序正使用更多的 CPU 资源和对你的系统造成更重的负担。对于资源使用而言，这些程序是字面上的消耗最多（top）进程。你必须承认，`top` 程序名字起得很妙。
|
||||
|
||||
最右边的`COMMAND`一列报告进程名（你用来启动它们的命令）。在这个例子里，进程名是`bash` （一个我们正在运行 `top` 的命令解释器）、`flask`（一个 Python 写的 web 框架） 和 `top` 自身。
|
||||
|
||||
其他列提供了关于进程的有效信息。
|
||||
|
||||
* `PID`: 进程 ID，一个用来定位进程的唯一标识符
|
||||
* `USER`:运行进程的用户
|
||||
* `PR`: 任务的优先度
|
||||
* `NI`: 优先度的一个更好的表现形式
|
||||
* `VIRT`: 虚拟内存的大小 单位是 Kib(kibibytes)
|
||||
* `RES`: 常驻内存大小 单位是 KiB (物理内存和虚拟内存的一部分)
|
||||
* `SHR`: 共享内存大小 单位是 KiB(共享内存和虚拟内存的一部分)
|
||||
* `S`: 进程状态, 一般 **I** 代表空闲，**R** 代表运行，**S** 代表休眠，, **Z** 代表僵尸进程，, **T** or **t** 代表停止（还有其他更少见的选项）
|
||||
* `%CPU`: 自从上次屏幕结果更新后的 CPU 使用率
|
||||
* `%MEM`: 自从上次屏幕更新后的`RES`常驻内存使用率
|
||||
* `TIME+`: 自从程序开始后总的 CPU 使用时间
|
||||
* `COMMAND`: 启动命令，如之前描述那样
|
||||
|
||||
确切知道 `VIRT` , `RES` 和 `SHR` 值代表什么在日常操作中并不重要。重要的事情是知道`VIRT` 值最高的那个进程是那个使用最多内存的进程。如果你在用 `top` 找为什么你的电脑运行慢得就像行走在糖蜜池时，那个`VIRT` 数值最大的进程就是元凶。如果你想要知道共享内存和物理内存的确切意思，请查阅[ top 手册][1]的 Linux 内存类型。
|
||||
|
||||
是的，我说的是 kibibytes 而不是 kilobytes。通常称为 kilobyte 的1024值实际上是 kibibyte 。 希腊语的 kilo ("χίλιοι") 意思是一千或者千（例如一千米是 1000 米，一千克是 1000 克）。Kibi 是 kilo 和 byte 的合成词，意思是 1024 字节（或者 210 ）。但是，因为这个词很难说，所以很多人在说 1024 字节的时候会说 kilobyte。所有这些意味着 `top` 试图在这里使用恰当的术语，所以随它去吧。
|
||||
|
||||
#### 屏幕更新说明
|
||||
|
||||
实时屏幕更新是 Linux 程序可以做的 ** 非常酷 ** 的事情之一。这意味着程序能实时更新它们显示的内容，所以看起来很生动，即使它们使用的是文本。非常酷！在我们的例子里，更新之间的时间是重要的，因为我们的一些数据（`%CPU` 和 `%MEM`）是基于上次屏幕更新的数值的。
|
||||
|
||||
因为我们正在运行一个持续的应用，我们能按下按键命令对设置或者配置进行实时的修改（也就是说，关闭应用，然后用一个不同的命令行标志位来再次运行该应用）。
|
||||
|
||||
按下 `h` 调用帮助界面，界面也显示默认延迟（屏幕更新的时间间隔）。这个值默认（大约）是3秒，但是你能输入 `d` （大概是延迟 delay 的意思） 或者 `s` （可能是屏幕 screen 或者秒 seconds 的意识） 来修改这个默认值。
|
||||
|
||||
#### 细节
|
||||
|
||||
在上面的进程列表里有一大堆有用的信息。有些细节看起来奇怪，令人感到困惑。但是一旦你花一些时间来逐个过一遍，你会发现，在紧要关头，这些是非常有用的数据。
|
||||
|
||||
第一行包含系统的大致信息
|
||||
|
||||
* `top`:我们正在运行 `top`！你好！ `top`！
|
||||
* `XX:YY:XX`: 当前时间，每次屏幕更新的时候更新
|
||||
* `up` （接下去是`X day, YY:ZZ`）: 系统的 [正常运行时间][2]，或者自从系统启动后已经过去了多长时间
|
||||
* `load average` （接下去是三个数字）： 分别是过去 一分钟、五分钟、15分钟的 [系统负载][3]
|
||||
|
||||
第二行 （`Task`）显示了正在运行的任务的信息，不用解释。它显示了进程总数和正在运行的、休眠中的、停止的进程数和僵尸进程数。这实际上是上述 `S` （状态）列的总和。
|
||||
|
||||
第三行（`%Cpu(s)`）显示了按类型划分的 CPU 使用情况。数据是屏幕刷新之间的值。这些值是:
|
||||
|
||||
* `us`: 用户进程
|
||||
* `sy`: 系统进程
|
||||
* `ni`: [nice][4] 用户进程
|
||||
* `id`: CPU 的闲置时间， 高闲置时间意味着除此之外不会有太多事情发生
|
||||
* `wa`: 等待时间，或者花在等待 I/O 完成的时间
|
||||
* `hi`: 花在硬件中断的时间
|
||||
* `si`: 花在软件中断的时间
|
||||
* `st`: “虚拟机管理程序从该虚拟机窃取的时间”
|
||||
|
||||
你能通过点击`t` （触发 toggle 的意思）来展开 `Task` 和`%Cpu(s)` 列。
|
||||
|
||||
第四行（`Kib Mem`）和第五行（`KiB Swap`）提供了内存和交换空间的信息。这些数值是：
|
||||
|
||||
* `total`
|
||||
* `used`
|
||||
* `free`
|
||||
|
||||
还有：
|
||||
|
||||
* 内存的缓冲值
|
||||
* 交换空间的缓存值
|
||||
|
||||
默认它们是用 KiB 为单位展示的，但是按下 `E` （扩展内存缩放 extend memory scaling 的意思）能在不同的数值轮换：KiB 、MiB、 GiB、 TiB、 PiB、 EiB （kilobytes, megabytes, gigabytes, terabytes, petabytes, 和 exabytes，它们真正的名字）
|
||||
|
||||
`top` 用户手册甚至显示了关于有效标志位和配置的更多信息。 你能运行 `man top` 来找到你系统上的文档。有不同的网页显示 [HTML 版的手册][1]，但是请留意，这些手册可能是给不同 top 版本看的。
|
||||
|
||||
### 两个 top 的替代品
|
||||
|
||||
你不必总是用 `top` 来理解发生了什么。根据您的情况，其他工具可能会帮助您诊断问题，尤其是当您想要更图形化或专业的界面时。
|
||||
|
||||
#### htop
|
||||
|
||||
`htop` 很像 `top` ，但是它给表格带来了一些非常有用的东西: CPU 和内存使用的图形表示。
|
||||
|
||||
|
||||
|
||||
这就是我们在 `top` 中考察的环境在`htop` 中的样子。显示要简单得多，但仍有丰富的功能。
|
||||
|
||||
我们的任务计数、负载、正常运行时间和进程列表仍然存在，但是我们获得了每个内核CPU使用情况的漂亮、彩色、动画视图和内存使用情况图表。
|
||||
|
||||
以下是不同颜色的含义(你也可以通过按“h”来获得这些信息，以获得“帮助”)。
|
||||
|
||||
CPU任务优先级或类型：
|
||||
|
||||
* 蓝色:低优先级
|
||||
* 绿色:正常优先级
|
||||
* 红色:核心任务
|
||||
* 蓝色:虚拟化任务
|
||||
* 条形末尾的值是已用CPU的百分比
|
||||
|
||||
内存：
|
||||
|
||||
* 绿色：已经使用的内存
|
||||
* 蓝色：缓冲的内存
|
||||
* 黄色：缓存内存
|
||||
* 条形图末尾的值显示已用内存和总内存
|
||||
|
||||
如果颜色对你没用，你可以运行 `htop - C` 来禁用它们；否则，`htop` 将使用不同的符号来分隔CPU和内存类型。
|
||||
|
||||
在底部，有一个有效功能键的提示，你可以用它来过滤结果或改变排序顺序。 尝试一些命令，看看它们能做什么。只是尝试 `F9` 时要小心。 这将会产生一个信号列表，这些信号会杀死(即停止)一个过程。 我建议在生产环境之外探索这些选项。
|
||||
|
||||
`htop` 的作者，Hisham Muhammad （是的，用 Hisham 命名的 `htop`）在二月份 的 [FOSDEM 2018][6] 就 [lightning talk][5] 做了一个展示。他解释 `htop` 是如何不仅有清晰的图形，还用更现代化的统计信息展示进程信息，这都是之前的工具 `top` 所不具备的。
|
||||
|
||||
你可以在 [手册页面][7] 或 [htop 网站][8] 阅读更多关于 `htop` 的信息。（警告:网站包含动画背景`htop`。)
|
||||
|
||||
#### docker stats
|
||||
|
||||
如果你正在用 Docker工作，你可以运行 `docker stats`来生成一个丰富的上下文来表示你的容器在做什么。
|
||||
|
||||
这可能比 `top` 更有帮助，因为您不是按进程分类，而是按容器分类。当容器运行缓慢时，这一点特别有用，因为查看哪个容器使用的资源最多比运行 `top` 和试图将进程映射到容器要快。
|
||||
|
||||
上面对 `top` 和 `htop` 中首字母缩略词和描述符的解释应该会让你更容易理解 `docker stats` 中的那些。然而，[docker stats 文档] [9]对每一栏都提供了有用的描述。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/top-tips-speed-up-computer
|
||||
|
||||
作者：[Katie McLaughlin][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[ypingcn](https://github.com/ypingcn)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://opensource.com/users/glasnt
|
||||
[1]:http://man7.org/linux/man-pages/man1/top.1.html
|
||||
[2]:https://en.wikipedia.org/wiki/Uptime
|
||||
[3]:https://en.wikipedia.org/wiki/Load_(computing)
|
||||
[4]:https://en.wikipedia.org/wiki/Nice_(Unix)#Etymology
|
||||
[5]:https://www.youtube.com/watch?v=L25waVhy78o
|
||||
[6]:https://fosdem.org/2018/schedule/event/htop/
|
||||
[7]:https://linux.die.net/man/1/htop
|
||||
[8]:https://hisham.hm/htop/index.php
|
||||
[9]:https://docs.docker.com/engine/reference/commandline/stats/
|
||||
Loading…
Reference in New Issue
Block a user